I had a chance to hear the Pico prototype at the Boston Meet yesterday. I was listening via HD650s to a mix of Eric Clapton and some Floyd and I have to say if I wasn't staring at the little marvel I would have sworn I was listening to a full sized rig. This setup had power in spades and fed by Justin's Mac laptop sounded fantastic. Great detail everywhere and plenty of, well, everything.
In full disclosure I'm not the world's most picky or particular listener and more than anything what I strive to find in a rig is something that when I turn it on it goes away and lets me enjoy whatever I'm listening to. Justin's amp had me tapping my toe the entire time I listened. I think the ultimate compliment that I can pay any piece of commercial gear as a DIY'er is to say that I'd buy it, and in this case that's certainly true. Seeing the craftsmanship, attention to every detail, and overall passion that Justin put into this thing it's pretty clear that anything I would attempt would pretty much pale in comparison. I expect this will be a big hit for him.