I don't know, I feel in many fights that at the end of the 3rd, i'm dying for more. I do like the half round to void draws though. I just think with all the build up to a fight, 2-1/2 rounds just isn't enough when you have a good fight going.
I wouldn't mind three 5 minutes rounds like normal for a main event, plus that half round. Vs 2 extra full rounds.