I've had one for a few years now. After my speakers it was my first piece of equipment better than the "big box" stores. A few months ago got a tube pre, a minimax, and have been switching back and forth between the pre's and a couple of the amps.
The purist has a more relaxed sound with a very black background while the tube pre is more forward, fells like your closer to the music. The tubed has a more locked in center image, but the purist has better soundstage depth and width. Finally with the minimax I get a little fatigued, never with the purist.
Right now, if I had to pick one, it would be the purist.
Might be a good time to look for a used purist, if IRD ever releases the audiophile, I bet quite a few will upgrade. Might drive the used price down.
FYI, I originally got mine used, and the guy who bought it emailed back a year later and wanted to but it back. Said he didn't find anything he liked better.
good luck, Ryan