What do you think of the Steinberg audio interface? It's more expensive though. Does the ADAT allow you to plug more pre amps into the unit without bypassing the preamps in the unit itself? Say I bought the saffire and a mixer. Would I be able to plug the mixer into the saffire to get additional mic pres?
The Steinberg MR816X has superior A/D conversion and preamps to the Saffire, but the D/A conversion isn't as good, and there are stability issues. The UR version has even more reliability issues. Once you get them working, they sound great, though. As good, if not better, A/D conversion than RME, plus better preamps.
Unless your mixer has an ADAT out, no. But you could buy something like a Behringer ADA8000 (yes, Behringer, but it's actually a very good unit, especially for the price), and you'd have 8 additional pres via ADAT.
Focusrite Saffire Pro 40 is pretty rock solid on the drivers. I had a Firepod before I upgraded to the Saffire and not only was the quality like night and day (though the Firepod had a more edgy sound to the pres, which I kind of liked better for micing guitars), but I've never had a single audio dropout or driver issue in general since I plugged it into my machine.
The M-Audio Profire 2626 is about equal in pres and conversion to the Saffire, but there have been issues with it in the past (mostly running it on Windows, where it'd give you a BSOD), and M-Audio has discontinued the unit, so I wouldn't expect any further updates or support from them.
For $500, you could buy a used/b-stock Saffire Pro 40 off eBay AND a Behringer ADA8000 (I actually have one I've been thinking about selling, if you're interested), and you could be recording 16 tracks right off the bat, within your budget.
