We've seen his FSU highlites, so just conentrate here on the MSU highlites, where he's playing against some really good competition with a very average QB.
Keon, insspite of geing a 4.5 - 4.6 guy, show the ability to win deep (explosive) and the ability to make guys miss and create space (YAC).
Like people get too caught up in just the 40. This kid gets to speed FAST, he's got incredible body control, and can win you 40 yards on any given play against multiple coverage.
In football, the reason you want explosive, is you effect the coverage and forces scheme to put extra resources so you can't take your top off. Keon Coleman, with ihs size, elite hands, body control, acceleration, foot quickness is going to create deep seperation, and thus eventually DCs WILL eventually shade coverage deep on him