After 25 hours burn in I have to say I'm well impressed. This amp does a great job of just getting out of the way. I've played sampler discs all the way through simply because everything sounds so remarkably natural and tracks I've previously found uninteresting or average are now anything but. This amp is weighty, dynamic, transparent and throws a massive 3D soundstage normally only found with megabuck kit. Lower registers are unusually detailed, bass textures never noticed before appear from familiar discs - and this is without any 'etching' or emphasis of highs. A friend with jadis and krell amps said he wanted an ska after only 10 minutes.
I was able to try the SKA in a system with densen CD, an ad815 pre and the JMLab alto be's. To say the sound was mindblowing would be an understatement.
Track after track was accompanied by the thud of jaws hitting ground and incredulous giggling. $200 amps shouldn't be able to do this. The air and soundstage was possibly the best I've ever heard, the room disappeared and tangible, palpable images remained in a walkaround acoustic. You could sit outside of the speakers and still hear (see) a 3D image. Large scale orchestral works were shown in a realistic perspective.
Thoughts of bass slam and treble sparkle seem utterly irrelevent when it appears you can reach out and pat Antonio Forcione on the shoulder. I've heard a few $100k systems lately, and I'd take this set up over most of them.

Congrats to Greg for producing a special product. This amp is a steal. --- Float, UK

In one word, the GB150D is, for me, precise. Imaging is excellent with instruments well placed and stable, i.e. precise. As ShinOBIWAN pointed out, instrument sizes are natural and not out of proportion. The precise characterization carries over to attack and decay of sounds as well. As others have noted the dynamics are superb. One thing I particularly enjoyed is the amps ability to reveal subtle detail in very dynamic passages. I am particularly fond of Beethovens Ninth, and there is a lot of subltle detail in the highly dynamic 4th movement that you may not be aware of if you have not heard a live performance. I use the word precise in the sense of being correct, with little error, not to imply clinical or sterile. I am not too good at assigning words to what I hear, so I will sum it up by saying the sound is Precise and Correct to my ear. Do not know what those words will mean to you, but they mean to me that I like the GB150D. --- Bill, US

Connected up the GB150D for the first time tonight. First impressions - uncanny silence even when I put my ear right against the tweeter - spectacular sound emerging from "black hole" silence ...... I'm hearing my cd's for the first time again. I'm beginning to appreciate how others have remarked about the non-fatiguing nature of the sound - long listening sessions are no problem. For the first time ever my wife has actually remarked about the wonderful quality of the sound. I'm spending long sessions not listening for details and the dynamics but simply enjoying the music! Still I can't help remarking about how much the extra headroom of this amp just makes the music come alive. Also, I'm struck by subtle detailed sounds I've missed before but also by the lack of "edge". This amp is really something special! --- Rez, Canada

Very impressive!
Most important thing first. Very first feeling was that now i listen Music, not voices. Detailed, and "smooth" at same time. Very, very easy to listen. Relaxed, airy, open and dynamic. Controlled and neutral but no any harshness or clinical sound. Overall treble is very good and suits very well to Orion and my taste.
All in all, SKA is very good simple amp design and i cannot resist to recommend to try it if possible. It is very easy to build and adjust and is not expensive. --- Pasi P, Finland