I got the amp yesterday afternoon and played it straight up until past midnight. I ordered it together with a Maxon OD-808 and use the pedal to push the amp for more distortion. And what distortion that is... pure creamy-crunchy heaven with a touch of fuzzy overtones!
My main amp used to be a Boss Katana. I get a great sound from it, but as good as the Katana is it just doesn't compare to a real tube amp. The sound of the TUBE15 is more 3D with more details, warmth and mass, it's more organic and jumps out at you better from the speaker. If you've got a good guitar (I play a Gibson SG and Les Paul) but don't own a tube amp yet, seriously, don't think any longer, get this one before they run out again! Best money ever spent on an amp.
I initially worried about not getting a good enough gain sound on lower volumes, but thanks to the Maxon pedal that's not the case. I'm playing at amp volume at 8 or 9 o'clock, and the pedal level at full to boost the sound entering the amp. Both the 15 watt and 1 watt setting on the amp sound great, the 1 watt being slightly brighter and thinner, the 15w is fatter and, of course, louder. The distortion cleans up beautifully with the amp gain or guitar volume pot rolled down, and the included real spring reverb sounds good as well.
If you're after a fantastic basic guitar tone (distorted and clean), get this amp and a booster pedal for thicker gain tones at lower volumes. You won't regret it at these prices. I'm selling the Katana.