we have a very similar player (jake long) and i think the consensus is to let him walk. the only difference is, we get nothing for long. you have a chance to trade revis and rebuild, you may even be able to get a qb out of it. revis is a great player and i believe he will recover from the ACL, but i think getting a couple of good picks and a qb to challenge sanchez would help you more.
If we trade Revis we also have a huge cap hit so that makes it very different and I don't think we'd get as much for him as we should based on him coming off the injury.