From 1985 through 1997 I worked in the Hi-Fi audio industry either installing or selling high end systems. Krell, B&W Nautilus, Conrad Johnson Art, Martin Logan Monolith or CLX, etcetera. I have also heard myriad configurations involving Wilson Watt, Mark Levinson, Pass Labs, Sonus Faber, and the list goes on. My ear has extensive training with live unplugged music as well...and while I don't know much about building tube amps, I can hear subtle nuances fairly well.
The short version is that the VTA ST-120 from Bob Latino is better than most amps that cost over $5,000. I was utterly shocked that I was getting this level of quality since I only paid around ~$1,300 if I recall.
I have the amp connected directly to the Oppo BDP-103 and then out of the amp directly into the Martin Logan Monolith III. A very simple three step for the signal. I have mid grade MIT wires. The Oppo is actively crossing the VTA ST-120 at 120Hz with the low pass going to a JBL powered 12 inch sub.
The sound is breath taking. One audiophile friend told me that it sounds better than the sixty thousand dollar system he had recently heard. Another audiophile told me it sounded better than a thirty thousand dollar pass lab system. Of course the amp is not the only component they hear, those Monolith III are serious speakers....that said however, i've never heard the Monolith III sound so natural and so rich and smooth. The detail is so natural that I just dream of listening to my system and I get so excited when i'm about to have a nice listening session. The vocals are the best i've ever heard period. Imaging is truly holographic...so stunning