Thanks Lance, that's very useful stuff...
There is evidence to support both sides of the argument so I doubt you can say that having a good vertical results in slower speeds. I believe that running is a complex skill in itself and maybe some of those guys with great power output haven't mastered it like others.
Evidence supporting low vertical (relatively) but crazy speed:
Jacoby Ford: 33.5 vertical, 9'7 broad jump, 4.28 40yard dash, 10.21 100m
DeSean Jackson : 34.5 vertical, 10'2 broad jump, 4.35 40yd
Evidence of great verts and speed
Trindon Holliday: 42 vert, 9'8" bj, 4.34 40yd, 10.00 100m !!
Calvin Johnson: 44.5 vert, 11'10 bj, 4.33 40yd <---- Crazyyyyy ass shitt
Also I know Bryan Clay has been tested at 43' and Harry AA at 40'