I watched a couple games of his just now.
I like that he's a lower body weight type of player, similar to Golden Tate and Chris Polk. He has decent balance for his size and spins out of lazy tackles fairly often.
I think the comparison to C-Mike is way off the mark. Michael had a 1.49 ten yard split and it showed on the field. Michael was freakishly explosive in the short area and was almost always running at around 100% speed/intensity. Prosise is much more like a David Johnson or Derrick Henry in that he tends to run at around 70% speed until he's in the clear. Once he's in the clear and squares his shoulders, he hits the jets and shows that he has an extra gear. This is in contrast to Michael who's extremely explosive and intense in short areas but lacks the extra gear at the top end. If anything, Prosise is the anti-C-Mike.
I think he's a very similar player to Dwayne Washington of the Huskies. Both are converted WRs to RBs with heavy legs and a blazing extra gear, and both are very raw as RBs.
Because RB is such an instinctual position, I generally dislike drafting "project" RBs who haven't shown instincts or natural aptitude, and this pick is no exception. Furthermore, I think Prosise is exactly the kind of RB that's only going to be as good as his blocking since he's always waiting for blocks and lacks decisiveness, short area explosiveness and recovery.
Basically, I think this is a good looking prospect on paper but looking at him on video I think that unfortunately he is not any better suited for our running game than Derrick Henry was. Sure, he can hit some home runs if you give him a gaping hole to run through, but he doesn't have much ability to create and he's too patient for Cable's system which requires extreme urgency and instincts.
I get why Seattle made this pick but ultimately I think it will prove to be a mistake. I hope I am wrong and that he develops, or, I hope that the OL gets so good that it won't matter even if I'm right.