Buffy did have great characters that I enjoyed for many years. However, the core of who each character really was never changed, or at least not anything as drastic as Wes or Cordy. Yes, Buffy had bad days like everyone but she didn't fundamentally change. She was still who she was at the core even after she came back from the dead. That's really the closest you could say that she changed was when she was despondent after coming back from the dead. However, by the end of the Season she was back to being who she always was, though granted, a bit more mature and serious. Willow gave the appearance of change, sure, but really, the most you could really say is she got more confidant over the years. Even her supposed turn towards lesbianism (which was handled very poorly) didn't really change her quirky, nerdy sense of humour. She was a student and learner throughout. I mean, I can see the same things coming out of her mouth in Season 2 that I could see in Season 7 and it would fit because she really didn't change that much. She endured much, true. But she didn't change. Naw, he was comic relief pretty much through the Season 7 finale. He may have gotten just a bit of depth here and there with Anya, but he never really grew much beyond what we saw in Seasons 2-3 of Buffy. I'll give you Spike. Tara never changed from Season 4 to Season 6 when she died at all. Anya changed very, very little throughout the years. Giles was static throughout the series. Andrew.....reallly?.....He was only on the show a couple years and really never got any development at all. Dawn went from super whiny to less whiny but that was about it. Granted, not everyone on Angel developed alot either, but no one on Buffy really moved that far from where they started in Season 1-2. Edit: Of course, it should be noted, Buffy wasn't about character change. Angel was intentionally focused on the next phase of life after Buffy (e.h. High School/College). This is why many have said it's a more mature show.....of course it was, that was the intent. It was about going out in the world, growing into who you are going to be which is exactly what the characters on Angel did.