I don't recall seeing any of Lee's Shippuden speed feats whereas I've seen several of Sasuke's.
So it's difficult to compare the two. But I'd say that without gates Sasuke is likely faster or has more potential to be BUT...
using gates Lee would trump Sasuke.
So Base Sasuke > Base Lee
Gates Lee > Sasuke
Lee no competition only a sasuke dick rider would say otherwise Sasuke probably has faster reaction time to Lee's attacks cause of his sharingan but Lee is faster, especially when he removes his weights.