Canelo Alvarez vs Kell Brook (who has the faster hands)?

Brook relies on timing. Canelo has speed, timing, and throws punches in bunches. Canelo with an edge

No contest in my opinion. Canelo punches faster for single punches or combinations. His punches aren't only faster but more accurate and much harder as well. Watch a replay of Canelo's one punch KO of Khan with the straight right or Baldomir with the left hook.He dropped them as if they were shot in the head and they were out cold for a long time. You won't find any punches that hard or fast thrown by Brook. Brook is a decent puncher with good hand speed but Canelo's punches are faster with more power and accuracy.

I'm not sure, I would have to compare side by side. I think Brook is more mobile and Canelo is more clever.

Canelo Brook isn't necessarily that fast, but has good accuracy and timing. Canelo has both those things but quicker with his hands too.

Canelo easily.