Like TJ, he's a little undersized but faster than average (TJ ran a 4.4 I think), runs great routes and has great hands. By the time Stepherson is an upperclassmen he could be that good.
Fuller is a really unique player based on his speed.. Stepherson already has better hands than Fuller, but not the take-the-top off speed against even elite CBs (Stepherson isn't running by Adoree Jackson).