I'd say Khan, some of his flurries are breathtaking. What fight would be Judah's prime? Tszuyu round one? He looked quick there, but I'd still say Khan.
Prime for prime (even though Khan hasn't entered his prime yet I don't think) it way too close to call... anyone that says otherwise is lying to themselves. Right now it's clearly Khan though.
if he could connect like judah did but khan isnt as awkard as juda is or sneaky khan wasnt faster then judah in that fight niether judah was faster then mayweather