I'd bring him back if i can get a reasonable deal, but if he chases the money I think it's a business decision. McClain is a quality MLB and has been playing it, but his play against the run far exceeds that against the pass, and you're starting to see each week a little more that if you stretch him to the sideline he can be a tick slow in reaction. He is also a little over aggressive on play action which leaves the seam open from time to time - I think he masks it a little though because he's one of the taller MLBs out there.
McClain is a very nice player, and I'd love to keep him, but I don't know how he will react when he gets paid, that so called rust - well, it's 14 games into the season. It should be off by now. At the very least, cleanup the repetitive mistakes.