Been using REAPER om my Mac with the M-Audio-FastTrackUltra8R. I use it mainly for punching in work for other clients (where they have sent me a ref track, and I'll return to them one or more individual tracks.) I have also done multi-track recording with this rig for a dozen or more instrumentalists. REAPER has always done the job for me - I applaud the technical philosophy of the developers, and you just simply can't beat the price!
I am active on the (
REAPER Forum). I know that Routing is a big topic, but I'd suggest checking in with the folks over there - that Forum has much the same Family feel as the AGF. Give 'em a try!