Sound_Forward, You sound just like me! I have a Multiface and also RME ADI-8. The last couple of days i've been mixing through my desk and back into the computer via the Multiface. I've been flicking between the mix straight out of my desk and the mix coming back through the Multiface and I just hate what it's doing - Pretty horrible degridation IMO.
I'm thinking of trying out the Tascam DV-RA1000. Have a look here:
http://www.tascam.com/Products/dvra1000.html
It can record in DSD format which is what SACD uses. I love analog too and whenever I work in a big studio I always print mixes to analog and digi. Come mastering time, the ME has never chosen the digi version over the analog. However.... A good analog 2 track isn't cheap, requires maintainence and alignment and if you wanna do multipul versions of mixes, takes up lots of tape.
Maybe the Tascam will be a good compromise? That's just a guess though at this stage.
Good luck.