Quentin Johnson is the boom or bust guy this year IMO, but I will gladly gamble on his measurables. I think other teams will too, though. Johnson looks like the only potential game-breaking receiver in this draft, so someone will take him early.
Addison is an easy yes for me, Flowers is an easy yes for me, both of those guys will be ballers. I am more tepid on JSN.... at 6'0" 200 with 4.5 speed, can he really threaten boundary corners? Gallup has a similar height/weight/speed profile, and even when he was good, CBs would cling to him like dog poo on a sneaker.