The thing is, playing another year at Iowa probably won't affect how many years he plays in the NFL, unless he gets hurt of course. If he gets 3 years by leaving this year, he would more than likely still get 3 years if he stays.
Some people love the college experience and some don't. That is the only real factor here. I bet he can't wait to get out after 3 years of being dissed by Kirk every chance he gets.
If he knows anything about Iowa Running Back Injury History ....I wouldn't blame him for taking risk of injury seriously. Just sayin