He's doubtless done some good things (or is trying to do) but let's not give the guy too much credit.
Mulroney's handling of the Crosstown file alone is frankly resignation-worthy. SmartTrack has plenty of blame to go around.
How much the Ontario Line routing is tied into what's going on with Therme is worth questioning. We could also get into the whole thing with the Osgoode Trees (specifically, the Minister's interference with the messaging). And THAT is without getting into the hypocrisy of them pushing the Bradford Bypass and 413 at the same time, if we're looking at transportation, as a whole.
At the end of the day, the Province's messing about with Metrolinx (not that other governments didn't do it too) will make it difficult when it comes time to sell the public on the fare integration. I'm cautiously optimistic they come up with something decent but, notwtihstanding that they have advanced some crucial infrastructure projects, I wouldn't give them a blanket, "They've been great on transit!" either.