My purpose and the rig is a little different, but I have RME HDSPe AIO in PCIe slot, and Profire 2626 through FW. The driver for AIO (Total Mix) and the driver for Profire are working together just great. This is for recording 4-piece band live, and doing it almost silently (except for vocals).
What I do is to feed instruments (keyboards, guitar effects processor, DI-bass) and mics to Profire (8 analog ins), and send them through AIO's ADAT in (Profire is clocked via AIO's ADAT out). AIO's MIDI receives MIDI triggers from E-drum brain. On DAW side (either Reaper or Cubase 6), I use Addictive Drum or Superior2 to play drum samples by the MIDI trigger. Each instrument is tracked for recording, of course. Then, use Total Mix to create four stereo submix, so that each player gets "more me" mixing. Four stereo submix from TotalMix are: ADAT1/2, ADAT3/4, ADAT5/6, ADAT7/8, and they are routed to Profire's ADAT IN. Those digital feeds to Profire are routed to analog outs (1-8), and each pair goes to headphone amps for monitoring. I can take a request, like "I need more bass with my drum", things like that, really on the fly (via Total Mix).
This is kind of Jamhub simulator, but using drum samplers and e-drum trigger, instead of drum brain's analog out (which is crappy IMO). The latency is very low (3-5ms RTL), since HDSPe AIO can handle 32 or 64 ASIO buffer very easily, and the drummer is very happy. When I need one more submix, I can use S/PDIF out from Total Mix, and feed it to another interface (UFX) running stand alone, and UFX drives two more headphones and analog out to monitor. But UFX is usually kept for my location recording, so I don't do that often.