It's hard to top Berto at the moment. You could make a case for Berto being on top of both categories.
Berto has the fastest hands, but he needs to work on his combinations. Don't get me wrong; he can throw them, he just chooses to throw one or two explosive punches at a time... Right now, Juan Diaz is the best combination puncher out there, by far. Maybe not the fastest, but definitely the most accurate and most effective.
he is not the fastest of course by a long shot, but cris arreola's combinations look great and are pretty quick for a heavy.
p4p i think its JC a man who walks around at 200lbs and fights at 175 should not have hands as fast as that
Yeah, they are. But, he throws one punch, resets and then throws the next. He's not as fluid as Diaz or Calzaghe...
You also can't forget Sergio Martinez. That guy has RJJ type raw abilities. Also, there is Andre Dirrell. He's also got amazing hand speed.