I just took some time to watch his HS film over at Rivals and I'm really impressed. I don't know if he was just always playing WAY inferior defenses but he put up over 1400 rushing yards and 21 TDs as a senior. His style and instincts remind me a lot of a slower, less dynamic Reggie Bush. He has a penchant for making guys miss and on more than one occasion completely reversed field and made a bunch of guys miss. Not a lot of power running and virtually no footage of him bouncing off tacklers, but a lot of jukes, cutbacks, and flailing defenders flying past him as they try to arm tackle him.
This is a youtube link to the Dematha v. Gilman game last year. Coker rushed for 392 yards and 5 tds against a very good team (2 other Iowa recruits are on defense for Gilman –Jim Poggi LB and Anthony Ferguson DE). There is one play at around 1 minute in where he breaks two tackles at the line of scrimmage and then runs away from the rest for 80 yards. This is impressive to me. He is 34 in white.
Enjoy.
[ame=http://www.youtube.com/watch?v=fDYDqguGW-I]YouTube - DeMatha vs. Gilman[/ame]