How would you describe the sound of Plinius IA's?

I can't say anything about the 8100, but there are some reviews here on the 8200 (esp. the MKII). I have the 8200 and would characterize it as warm. It is definitely not bright! Not in my system, anyway.

I recently trialled the 8200 Mk II against a McIntosh 6500. The Mac won for musicality and listenability. I found the Plinius excellent for detail and resolution -- each instrument clearly 'visible', etc. Ultimately I thought it got too much and chose the Mac. I think the way I would put it is that Plinius plays the instruments well and Mac plays the music well.
Despite that, the Plinius is also a very good amp if you like that sort of thing. Very muscular and buttoned down, not fatiguing, quite impressive.