Power. Look at slugger Rene he ended up falling short against glass jawed Amir and lacking in heart Devon. Cotto(e) is known for having good power. It didn't do much for him against speedy emmanuel and iron chinned margarito(e).
yessir all the main characters of their era had good handspeed. Joe Louis, SRR, Muhammad Ali, SRL, Pernell Whitaker, Mike Tyson, Roy Jones, Floyd Mayweather, etc. Ali, Pea, and $ all aren't punching power masters. Pea is even feather fisted. There's a ceiling for guys who aren't fast imo.
true, like when people ask who's the fastest boxers of all time, they usually end up naming some of the best. But timing is even more important