I waited 45 minutes at MIA on December 26th, which seemed rather long. But, it seemed very busy at that time (the nearby carousels were all pumping out bags for other flights too) and it was a 772 flight so didn't seem all that bad to me. There was an initial mix of priority/non priority bags and then just priority bags -- and mine came out relatively early on.

Worse experience I had was at RNO in September, there was very few other flights that arrived at the same time and it took a full hour before the first bags came out, and without any priority given I didn't get my bags until about an hour and 15 minutes after touchdown. My relatives that live there tell me they always wait a long time for bags.