I loved it. What better metaphor for an empty suit than an empty chair.
True, he stumbled over his delivery and you had to listen but if you did, oh did he say things that needed to be said! No one has taken Obama to task for unkept promises and plain ineptitude quite like it.
Don't forget he ad libbed it. How well could the talking heads do without their scripts under the same circumstances. They were well primed to find fault.
Let's consider content over delivery. Risque? Poor taste? Only to the holier than thou types. Obviously they were in the minority in the live audience. They appeared to love it.
Call him all the disparaging things you can think of. Tell him how he's embarrassed himself. Deny anything he said was true.
Then go out and get a life. It was fun. It was a nice break from the rubber stamp speeches that came before and after. At worst he brought to mind Presidential failings and told us it's perfectly okay to fire the guy. At best, he made my day.