As a Bears fan, lemme add a few things....
St. Clair was set to start at left guard when Chris Williams got injured and he get's thrust into the starting left tackle role. He can play very well as a backup at RG, RT, LG and LT. He's a very versatile lineman who is the kind of guy you wanna have around. He did give up a pretty large number of sacks if I'm not mistaken but he wasn't as bad as the stats show him to be. Remember, this is a Bears team that's offense was supposed to rank 32nd, and the line was considered completely horrible. We even lose our starting, first-round left tackle and at one point have the #2 offense in the league. You guys are lucky to get him.
If he can help Brady Quinn to a Pro Bowl next year, I'm all for it. I wish he had some OC experience, but he's been in the business for awhile it seems, hopefullky this'll pan out.