I found his interesting essay on the episode Intervention and it opened my eyes on facts I have never noticed when watching the episode. I wanted to share it with you all. Here you can find the whole essay.

These are some points I thought interesting: 1- To begin, I’ll use two quotes - one from the beginning, one from the end, that establish how the theme is explored:

Spike, talking to Warren about the Bot: ‘Some say it's better'n the real thing.’

Buffy, talking to Spike about the Bot: ‘That ... thing, it ... it wasn't even real.’

The Bot was built to ‘love’ Spike, to interact in a certain way. What can that tell us about Spike’s view of love? Spike is evil and soulless, can his love be real? Buffy fears that she is losing the ability to love - is that the reality? The Scoobies do not realise that the Bot is not the ‘real’ Buffy - and so on. Love and reality.

2- One major plot-point in the episode is the fact that the Scoobies think that Buffy is sleeping with Spike. Now the whole having-sex-with-Spike-thing in s6 is very interesting in the light of this. The Scoobies assume that Buffy has probably gone slightly insane, what with her mom dying and a hell god wanting to kill her sister. And (surprisingly?) - they are actually incredibly nice and open-minded about it! Especially Willow, who is rather insightful:

Willow: I, I'm just trying to figure out why this happened, and I, I think with ... your mom and everything ... everyone was being all sympathetic, and, and making you feel weak. A-and Spike wasn't like that. So, just this one time, you just ... did something kinda ... crazy.

Now this is sort of reversed in the start of s6, when Spike is the only one being sympathetic and letting Buffy be weak. And it shows that Spike understands her very well, and Willow seems to get that. So when Buffy later in the episode finds out what happened, and for a short time has to deal with ‘you slept with Spike, but we’re trying to understand’, it’s not that bad really.
So I think one of the main reasons she keeps it so very quiet in s6, is that if her friends find out, they will stop her from doing it again. In Intervention they are very understanding and gentle, but they want to help her STOP! And s6 Buffy for a long time doesn’t want to stop - at least not yet! Since Spike is her only outlet, she wants to keep him there - just in case. And her friends would never let her be able to do that. But they wouldn’t be able to provide another outlet either, so she sticks with Spike until she finally finds the strength to stop.

3- Xander goes to talk to Spike, to stop him from ‘taking advantage’ of Buffy. The following conversation ensues (these being the main parts):

Spike: She's upset about her mum. And if she turns to me for comfort, well, I'm not gonna deny it to her. I'm not a monster.
Xander: Yes. You are a monster. Vampires are monsters. They make monster movies about them.
Spike: (sarcastic) Well, yeah, you got me there.
-
Xander: Spike, Buffy has lots of friends, and we love her very much, and we'll do whatever it takes to protect her. Now if that means killing you, then, well, that's just a bonus.

And isn’t it interesting how much more sympathetic Xander is here, compared to Entropy/SR. This is Xander with his life sorted, who wants to look out for his friend who’s obviously gone off the rails. As he says in SR, Buffy’s private life used to be his business - here he doesn’t even hesitate in confronting Spike.

Also, he is sure of who Buffy is. He knows her well, and understands that only something extraordinary would make her behave in this fashion. But by the end of s6, he is confused about everything, and he realises that he doesn’t understand one of his best friends anymore. 

4- On a side note, this episode is Spander extraordinaire. I mean these lines alone:

Xander: No one is judging you. It's understandable. Spike is strong and mysterious and sort of compact but well-muscled.
Buffy: (firmly) I am not having sex with Spike! But I'm starting to think that you might be.

And later:

Xander: God, I feel ... kind of bad for the guy. Gets all whupped and his best toy gets taken away.

Actually Xander is friendly towards Spike all the way up to ‘Afterlife’. They’re not friends, but reach some sort of mutual understanding. Only as soon as Buffy’s back, it stops. But then Xander never liked Angel either, he obviously has problems with his hero having non-human (boy)friends. It’s no surprise that he’s the one who tried to salvage her relationship with Riley!

As concerns Willow, her main worry upon finding out in s6 that Buffy has been sleeping with Spike is ‘Was I the only one who didn’t know? She’s concerned she was ‘left out’ (I guess those nerd-issues run pretty deep).

There are more points that I liked but it'll turn this post into a very long one. 

It's better if you read the essay from the link I gave.

Don't forget- Buffy even explained Spike's reasons for having the Bot made, in that episode.  She says to Dawn, "Weird love's better than no love."

I didn't read the essay, so I don't know if that was pointed out.  That quote is the reason I see the Bot as sad, not creepy.

FetchingMadScientist

In s6, Tara was the only one who said "Do you love him?  It's okay if you do.  He loves you."  Dawn sees it in s5, but doesn't see it as disgusting.  Giles saw it as the inevitable was my impression at the end of s6.  The role reversal of Xander was interesting as well, although, he did just see his ex fiance get screwed by the vamp in question, so that probably fueled his anger and misunderstanding.  Had Buffy come clean initially about what was happening between her and Spike, I think Dawn, Tara and Xander would have supported it, Anya indifferent, Willow confused (as she is at the end of SR), and Giles upset, but again, he saw it coming, I have no doubt about it.

I'm not sure if the essay brings this up, because I haven't had a chance to read it, but between the whole what's real and what isn't, it's clear that by the end of Intervention that Spike's love is real, even though most people on the show at that point consider him to be an inanimate object (which was incorrect, even if his love for Buffy wasn't true) and therefore not a "real" being.

Oh yea, just wanted to add that Buffy continued the "Spike is evil" trend by telling her friends that Spike was the Doctor in s6, even though it wasn't 100% true. Stupid Riley.  Stupider Buffy...

The Buffybot is a very interesting character in her own right - whatever she says becomes true/prophetic for the real Buffy.  She has sex with Spike after a fight - later Human Buffy does; she tells the gang that they have to rescue Spike and they do, even though Buffy plans to kill Spike to keep him from telling Glory about Dawn; Buffybot says you have to see Spike naked and Buffy eventually does;  Buffybot gets "killed" when she's fried with electricity - Buffy is killed (or commits suicide) at the end of the season.  In the next season, Buffybot is physically torn apart as Buffy is returning from heaven - Buffy is subsequently torn apart emotionally by the demands of her friends and taking care of Dawn and abusing Spike. 

What's most interesting is that none of Buffy's so-called friends recognize that the Bot is not the real Buffy, no matter what kind of crazy thing she says or does, Willow and Xander don't figure it out until Human Buffy appears and the two are standing next to each other.  None of Buffy's friends (including Spike) recognizes that Buffy is not really herself after the Faith switch either.  Only Tara, who has never met Buffy before sees that anything is wrong. 

Spikez_Tart, now that you mention it, electric like currents go through Buffy as the portal sucks out her blood, doesn't it?

And for Faith in Buffy's body to tell him that it would be "wrong" for her to be with him/sleep with him, is wickedly weird, considering she was dying to get into Angel's pants, and knowing that vampire stamina would be better than a human's.  Hell, almost anybody would be better in bed than boring ol' Riley.  I didn't get that part, except unless she was trying to show Buffy up in the bedroom since she couldn't in regular life (slaying, family, friends... meh).

 electric like currents go through Buffy as the portal sucks out her blood, doesn't it? - DEFINITELY.  The Bot is almost a precursor of Buffy's death, not that there aren't other foreshadowings, and when Buffy comes back, the Bot is destroyed. 

The whole thing with Faith in Buffy's Body and Spike is weird in a totally flamable way.  I'm pretty sure that Faith grabs Spike's 

crotch at one point.  The camera is on his face and he flinches.  

Faith sleeps with Riley (and it's not even clear how she knows about or finds hime) in order to piss Buffy off.  Why not sleep with Spike?  That would really send Buffy into orbit.  And the fallout would be beyond belief.  Damn - how did Joss miss that one?

Sorry for weird typing.

I think the reason Faith sleeps with Riley and not Spike is because she's not just trying to piss Buffy off. She wants to BE Buffy. She's sick of Buffy getting everything and her getting nothing, and she wants to know what it's like. If her plan had gone off the way it was supposed to, Buffy would've never gotten her body back and never known what Faith did with it. So yeah, sleeping with Spike would've been fun (and foolish Faith for passing up the opportunity!) but sleeping with Riley gets her the loving boyfriend that Buffy's always had and Faith's never had.

And as for how she knows about Riley - when she's still in her own body, she spies on the gang at Giles's, and she sees Buffy and Riley being (gag me) couply. Also, I think Willow mentions Riley when they're at the Bronze. How she knew where he lived... well, that I don't know.

She definitely grabs his crotch, and probably massages it too judging by the look  of arousal and desire on Spike's face, and the anger and frustration when he realizes that no, he would not be having sex with Buffy like she strongly (well, Faith strongly) suggested.

As for being Buffy... true, but nothing screams "Buffy" like having sex with a hot vampire.  Silly Faith.

I agree with Eowyn325. I think it's because Spike didn't mean a thing to Buffy at that time, Faith went after Buffy's boyfriend, she wants to live Buffy's life with the friends, the family and the boyfriend.