I just turned into an M-Audio fanboy - here's a field report for everyone who wants to buy an audio card for Vista:
* I was looking for an audio interface with MIC preamps that works with Vista pre SP1, because due to some Windows cockup I am not able to update to SP1.
* First one I bought: Echo Audiofire 4, nice card, but ocassionally applications had issues with it and its latency was ok, but not that great (12ms). Perhaps because it's firewire, so I decided after half a year of using it to go back to start and get a USB one.
* M-Audio MobilePre USB: bus-powered. downloaded drivers, plugged it in, worked straight away, latency in Cubase 4: 8 ms, brilliant, BUT - damn, I need MIDI input as well - so I went back to the store and they kindly exchanged it for a ...
* Edirol UA25-EX: bus-powered too, MIDI, pre-amps, BUT test under Cubase 4 -> 23 ms
* M-Audio FastTrack Pro bus-powered, MIDI, pre-amps. They supply drivers for all flavours of Vista including pre SP1 and all of a sudden I am back in low latency land, halleluja -> 8ms
I guess there aren't that huge differences in hardware, but M-Audio just constantly keeps updating their drivers and that makes their products work well. So here is my 2 cents (ok, I already provided 2 dollars): Go to the download page, look at the drivers for the product you intend to buy, if the version sits at 1.0 for 2 years, then be suspicious.

