I can't stand CI. I love the original Law & Order and, although I didn't at first, I mostly like Special Victims Unit (I don't like Christopher Meloni's character, but I was a big Munch fan from the character's days in "Homicide"). But I think CI is a fantasy of a "superhuman", never mind abusive and possibly above-the-law, cop. Since I'm not into fantasy TV, I find this very annoying.
No, I don't think Vincent D'Onofrio is very good, at least not in CI, and yes, I've seen more than one episode. I've seen worse acting and worse casting, but I wouldn't give him any awards (or pay him what he's probably making). Just my opinion.