If a wrestler is going to secure one take-down per round and have it win the fight, I'd rather watch a wrestling-based fight for 12.5 minutes instead of 15.
And Squirrelfighter, you don't understand when it comes to cardio. Anyone at the UFC level can fight for 25 minutes. But it's a very conservative, low-risk fight. Fighters are free to use their gas tank more explosively and aggressively in a shorter fight, that point is not debatable. You simply can't be in good enough shape to go aggressive 100% for 25 minutes, human bodies don't work like that. Jose Aldo is a GREAT example. He gives almost the same amount of aggressiveness in his title fights as he did in the 15 minute fights, and he's always gassed and disengaged by round five.
I'm not just a fan I'm also a practitioner, so yes, I do "understand" what it means to have that kind of cardio.
As amazed as I am to be quoting Nick Diaz he said plainly that its bullshit that fighters gas out the way they do. He knows he can go at full speed for five rounds at 80% of his anerobic maximun, because through his Triathalon training he spends hours at nearly 100% of his anerobic max. And if one fighter can train hard enough to get into and stay in that kind of shape, and he only fights once every 3-4 months, what is the excuse for another fighter not being able to do the same when he fights with the same regularity?
As I said I'm against the 5 round main events. But I definitely think its a cop out to say fighters physically can't do it, when there's overwhelming proof that it is possible.