Just played one of these for the first time a couple of days ago. I've played the 212 combo in the past - which I liked a lot, but I understood that it was tonally different than the little guy.

So I played the little guy for a few minutes. Overdrive channel was calibrated a little 'crunchy' for my tastes. Was OK with minimal gain, or with moderate gain for classic rock stuff. But forgettable.

But the clean channel was quite nice. 6L6 power tubes are a weakness for me. Nearly Fenderish tones were possible, and a few other clean variations. The speaker was not obviously holding it back. But I'll wager that with a better speaker and upgraded tubes this could be really special.

Good volume, good size. Construction was definitely to a price point, but seemed good enough. $199 used plus tax.

Why were these not a bigger hit? Or did I miss something?

Heard lots of talk about the Valve King when it came out, so I tried one of the 1 x 12 models 50 watts. Not good enough to make me flip my Classic 30 for it. The VK sounded a bit flat lacking depth to the sound . That might be the speaker .
I tried a 2 x 12 VK a year later and thought it sounded much better , like a totally different amp.

I have the 2 x 12 combo and it's very versatile. I play a lot of metal/hard rock and even straight out of the amp it sounds great. The only thing I add is a BBE Sonic Stomp in the effects loop and a tube screamer in front of the amp as a clean boost (gain on 1-2 at the most) and it tightens up the bottom end and boosts the mid's just bit. I am going to re-tube it at some point which should really make it sound even better. Not a bad amp for $600.00 The clean channel has a Fender like sparkle when the bright switch is engaged (but I usually don't run it that way as it can be almost two bright) but overall a great clean sound.