I'd definitely go with Ray Rice. No question. Someone mentioned the back that will get you 4 yards on 3rd and 2.
He is a true RB, not just a runner. Setting up blocks is such a critical skill for a RB, and I think he does it better than anyone coming out, by far. Living in the NE I've watched him quite a bit, and he translates well to the NFL imho.
With Felix, while I haven't seen him as much, I get the feeling he is like a Reggie Bush. We see how well that is working out with his 3.5 ypc. He'll rip a long run off no doubt, but I think in the NFL when talent is so much better, he won't be able to outrun as easily, or more importantly frequently to the corner.
I'm all for Ray Rice, trade an early pick for Roy W (if that rumor is true), and then pick up a CB. 3 key areas of need, Ray won't need time to "develop", neither will Roy who would be the 1st WR in this draft, even at that old age of 25 that seems to scare board members away. And as for CB, well we saw Reeves get picked on too much. Could be a function of lack of pressure (don't tell me sack numbers), or just could be he's not that good. Either way, you'd like to have some options other than forking $80million over to Newman.