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.
I don't disagree that sometimes I'm dying for more after the 3rd round. But the difference is - that's VERY good for the sport. If you're dying for more after a fight, that's the best possible outcome. If you're over-saturated (like if every fight was 5 rounds) you'd be so sick of MMA by the end of the card. Law of diminishing returns.