i couldn´t use it in my old ASUS A7V266E (AMD) motherboard because it stuttered and had to use an Audigy 2 instead. However in my new ASUS A8N-SLI Deluxe it is running like a dream. i was using the ASIO drivers in all cases. i have done many successful 5.1 surround mixes with both cards.
I've been using a Revo 7.1 for about a year. I have it matched with a set of El Cheapo Monsoon surround speakers. They sound great to me. Makes for a very nice system for building 5.1 toys in Vegas and doing cute demos of your audio wizardry.
I bought the card based on a recommendation of M-Audio products in general by Spot when I was on the hunt for a PC based surround system. I highly recommend it.
I too have this card and it's ASIO is great, I have some cheap Altec Lansing speakers attached and they sound great. The card has some descent support features too. I have had it in my PC about a year too.