I have KBB, Cliffs & Barrons.
KBB is very general. I would definitely supplement it with another material.
I read Cliffs and Barrons together. They both have their strengths/weaknesses. Some stuff I understand better the way Barrons explains it, and some stuff is better explained in Cliffs. I also think the pictures and stuff in Barrons is a little easier to understand than what's in Cliffs.
I know a lot of people just buy Cliffs + Destroyer, but with how "random" people say the Biology section is, I want to go through as much bio material as possible. I also bought Campbells textbook and I plan on reading chapters 19-21..