Derwin is a stud. Has all the general attributes you want (speed, height, jump), great coverage, great run stopping, great catching, and is an excellent candidate for pick artist.
In different formations I have him in the box, playing nickel, and playing deep safety. Not only is he extremely versatile, but he is among the best at every aspect. Dude can handle everything.
If they hadn't rereleased him (which I'm surprised I didn't hear more about cause it was f'd up on EA's part) he might very well be the most expensive card right now, and deservedly. ATM I'd say Derwin and Dave Robinson are tied for best defensive cards.