They all perform about the same...
I actually went with the ECS sis 755-a2 board...I know, I know, ECS...BUT, my old ECS SIS735 board served me well..
This one is prett zippy...the IDE performance is nice 🙂 games run the same as the other boardsin the 754 range...the only thing it lacks is Firewire.
If you don't like ECS, Asrock makes a 755 board. I suggest you look into them.
I tried the kt800 and nforce 3 boards.
both are equally nice.
Nforce 3 has the built in firewall and some of the boards have giga lan...
you know, in the end, it really doesn't matter 🙂 just pick featrues you like.