Replacing BB5 disc brake pads with BB7
 

After hearing that the bb7 brake pads are much superior than the bb5's I went and bought some Avid disc brake pads to replace my bb5 pads. Package says it fits bb7 brakes but not "ball bearing five" brakes. After reading many people's opinions it sounded like I could replace bb5's with bb7's no problem. I'm confused.

the pads are different

Not interchangeable. Different shape and size.

Maybe you were hearing that BB7 brake pads and Juicy 5 brake pads are interchangeable, which they are. The pads from the Juicy series and the BB7's are interchangeable. The BB5 pads, as others have already said, are completely different.

You can replace the calipers, no problem, but not just the pads. By the way, upgrading my calipers from BB5 to BB7 was the best upgrade I've made, well worth the cost.

+1 aFAIK, The brakes them selves are better .. upgrade the whole caliper,
you have 2 pad wear compensation knobs for the most obvious improvement.