I read Darkhawk up to maybe #25. I don't remember much about it, but it was alright. Nothing that would compell me to re-read it (if i still had them). I think it was closer to Nova than ROM. ROM was a million times better (and I re-read that whole series about a year ago)

I bought the first couple issues of Sleepwalker and I lost intrest. I also bought some later issues with Spider-Man, but again, not enough intrest to keep buying.

Since you have the books, you should at least give DH a shot. If you don't get into it after a few issues then you probably wont like it