Picked up the first couple of each season. I am also liking the Angel and Faith book a little more. The story seems more straightforward so far. And yes, I agree, the tie-in to Angel 6 was late, seems a little forced (to dovetail those two different books/seasons) but I appreciate the effort at least that if you did invest in the IDW Angel, they are retconning it so it wasn't a total waste. I did give it up mid-way myself, though. The Angel/Faith artwork is better, too.
The Buffy book seems to be starting a little slow. I am not liking her or Willow yet. But I think I'll hang in there, see where they go with it.