I don't know of too many 6'5, 225 lbs WRs. I agree about his arm. But he still has a couple of years to improve enough to where he can be more like Vick (have his running make up for his lack of accuracy).
I don't see him as a WR though. Size and speed is not what seperates the upper echelon of WRs from the others. Route running and catching ability are far more important.