Here's my take on it after a lot of question to people who use baitcasters and swear by them plus watching the pros on TV comps and dvds.
Baitcaster pros: less weight, more line capacity, better control (1 handed casting), heavier drag, more options(gear ratio), less line twist, manages heavier lines better, handles heavy lures with a smaller sized reel vs spinning.
Cons: They don't handle lighter lures very well, not very good with light lines, harder to learn to cast,
Is fun trying to learn using it as I see people using them single handed with such accuracy that I want to be able to do that as well.
Cheers, Mark.