I think he's a pretty good center, but more importantly, he will be available for games. IIRC he's only missed 3 since joining the NFL.
My biggest problem with Unger was his injury issues. Secondly he whiffed on a lot of blocks. I swear he's had unreported concussions in the past. Watching Superbowl 48 he flat whiffed on "Pot Roast" a couple of times and would throw his arms up in the air and look at the ground. Not sure if DTs are fooling him with which direction they are going or if Unger just blows it sometimes.
And by Max's own admission, he would get blown up by Mebane in practice almost everytime.
I like Unger, and I appreciate his time here, but we have been needing an upgrade for some time, and even and average Center is an upgrade if he can stay on the field. Continuity means a lot to Olines.
Edit: Link to discussion about Wiz in NFL Forum:
viewtopic.php?f=4&t=109387