I just got my 2011 a few weeks back, the manual says to run only 87 octane. I wouldn't run anything other than that.
Had a 99 Camaro V6 and used to run higher octane gas in it frequently. The dealership service department told me they highly discourage running anything higher than 87 in a V6 engine because the engine is not capable of the higher compression required to ignite the higher octane gasoline. They also told me that a carbon buildup occurs if you run higher octane gas in a V6.
This is just what I was told, I'm no expert, but I wouldn't run anything in the engine that the manual doesn't suggest. There's a reason why they say to run 87 octane and not 87+. The engine is designed to run the 87 rated octane gas.