I thought he did a good job while he was here. He helped bring in some good players, and I didn't really have any complaints about his performance as a GM.
I'd say that he was a safe choice for USC, that he knows his way around, and can do the job. They basically threw everything at him after their first choice, Courtney Morgan (Crimson Tide), turned them down.
I don't blame his wanting to leave for USC, especially if they upped his salary, gave him more power, etc. When he left, he did so at a time that was good for everyone around, and didn't leave us hanging out to dry like Brian Kelly did.
That being said, I see Mike Martin as an upgrade.