Not counting attitude/personal stuff or contracts:
I'd trade him for Gresham in a heartbeat. And by heartbeat, we're talking hummingbird heartbeat rate.
I wouldn't trade him for Miller or Gates, but that's because of age. If age wasn't a factor, I'd take Miller in a heartbeat. I think Gates has lost enough that he'd be too much like a poor man's Gronk, so I'd probably pass on that one.
I don't like Finley's attitude, so I wouldn't make that trade, but Finley's got great ability and drops the ball a lot, just like Hernandez.
Moeaki's a better blocker and lesser receiver, but he gets hurt even more than Hernandez, so I wouldn't make that deal. Again, though, the talent's there.
That leaves Pettigrew, and I'm not sure how much I'd trust him as a former Lion. That's a team that's skewed numbers and screwed up players. Again, though, he's a better blocker than Hernandez and a lesser receiver.