I was going to buy one of those mainly so I could connect it via adat to my motu, and bypass the preamps and use outboard preamps as I please. But I went with the echo audio fire 8. Just bought it actually, it's in the mail. They are hard to find because so many places don't carry them anymore, but it's basically a sweet a/d converter with line inputs for your external gear.
. Under $600. FireWire/adat.
The art tubeopto was a close second. But you should be able to bypass the preamps via quarter inch on the combo jack. Someone correct me if I'm wrong!