I still loved Buffy as a character but I didn't respect a lot of her decisions that season. In regards to the episode in question, Giles was right about Spike being a threat and needing to not being around the people who Buffy was supposed to be protecting. But at the same time Giles would have never gone behind her back like that so I was very upset with that episode and the way that her relationship with Giles is sacrificed to bring SB closer. As you watch the rest of the season you'll notice that a lot of the other relationships are sacrificed for SB moments.
Because nothing says a love story like degrading a character and breaking up her support group to make it work with the guy that attempted to rape her