Yeah, I'm just a fan of the design principles and ethos and of course the sound.
I can tell you that the feel/haptics of these amps is top notch, as familiar as with the V200 and lesser models, only much grander and imposing. The volume knob is one heavy single piece, very firm and secure, and it needs to be. Plenty of High End units I tested on the show have rather loose knobs, for frickin' 1000+ Dollars. Unacceptable.
The front panels are strong and heavy and in one piece, cut with finesse and precision like the victims of the Fookin' Legend of Gin Alley. The units are indeed like a V200/V800 combo in height but much deeper.
Thermal design is no problem, these amps were running for hours already when I visited with multiple headphones connected and the units were just warm.
I like to refrain from sound impressions on a well-visited show like this as the ambience level doesn't meet the criteria of a good impression and open headphones like the HD 800 are especially vulnerable. I checked out a few headphones I know and listened to the V281 unit for a while. What struck me was the tight iron grip on the bass of the TH-900. I am very familiar with that phone and though it theoretically belongs to the easier to drive headphones the bass part of it demands a quality amp. It needs tight control and balance and it shone on the V281, effortlessly while the volume knob was laughing at me. IIRC the knob was at 8 o'clock, being loud enough and I'm never the type to drown ambience with the knob, I have a good feeling of volume control with regard to possible hearing damage but I am not a low volume listener.
On another note: The HE-560 is amazingly articulate, well-defined in imaging and the bass does what HE-400/500 didn't - yet having volume, tactile impact and the precision/texture - clearly a winner to me and the only new headphone to create a little wow effect. The built needs to be improved and it will - listened to it both at Hifiman and Violectric and it was impressive. Can't say the same about the Oppo...