If your talking about the 96/24 audiophile firewire I've been using one for around 9 months. I use it for a coax to firewire converter for my lap top when recording to 96/24, which is about all I record to these days.
I do use the aux sends on 1 and 2 and the headphone outs to monitor my mix from a sound board when working with bands doing sound.
For what I use it for it works well. However, make sure you get one with the latest software upgrade or down load it from M-audio's web site.
I maybe looking to move mine and would let it go cheap if the planets aline perfect. Offer me a price if you want it and I'll consider it.
Ray