Rich,
We haven't had a chance to play with the Pre-2 DSP, but we have auditioned the Audio Refinement Pre-5, which is an analog-only preamp allowing for a 5.1 source. The Pre-5's preamp section was suppose to be slightly better than the Pre-2's, and at one point in time there was a Pre-5 DSP planned.
The preamp section of the Pre-5 was quite good, better than the Sunfire TGII and B&K Ref30 we auditioned, and almost on a par with the Anthem AVM-20 v1 that we ended up purchasing. If we didn't need a preamp with digital processing, we might have gone with the Pre-5.
The source we were using with these auditions was the Audio Refinement CD Complete. To the ears of my wife and I, this was the best sounding CD player we auditioned costing less than $1500 (and believe me, we auditioned a lot of them!

). This has been our CD player now for over 3 years.
Just some anecdotal information about Audio Refinement.
Michael