Thanks for the "plug" DB
The VT are the most "organic" modellers...but the least flexible. They just don't have the sheer number of options or the versatility compared to say a Line 6 Flextone/PodXT/XTL, or Roland gear. I miss my POD XTL, cos I can get real close to *my* sound out of it...which is a 800 marshall blasting through GB25s. Can't get that on a Valvetronix.
That said, The VT have a good dose of tube warmth/compression, and respond to the touch AND the volume knob the way a tube amp does. Its not JUST like a tube-amp, but FAR better than the all digital amps. It's effects are also more organic or realistic.
I have owned the 15/30/50 combos, the Da5 combo (no tube), the ToneLab SE, and have put in a few hours on the "blue" combos (60/120).
For the small combos:IMO/IME, avoid the AD30VT. Its the worst of the bunch IMO..at least in stock form. Its the fuzziest and grainiest sounding, as well as the least "tight" or the sloppiest. It also has the least authentic sounding models...everything is a little "scooped" sounding...not full. I'd hope a new speaker would take care of it, but I don't know.
The 15 and 50 are MUCH punchier and tighter, and the models sound more "authentic". The 50 is the best of the lot simply for the fact that you have a speaker out, AND the wattage selector. The 15 watt does not have the speaker out or wattage selector. The 15 sounds AWESOME when ya get a little volume on it, but does lack some punch and fullness without the wattage selector. Its a dang loud 15 watts, but thankfully doesn't need to be cranked too much to get good tones. It also sounds much better at low volumes if you get it off the floor.
The Tonelab SE...I did not have good luck with running through my Atomic...it was small sounding, thin, and lacked a "real amp" tone. It sounded like a recording of a recording, no matter how much I played with it. The POD XTL on the other hand was full, punchy, and sounded more amp-like through the Atomic. A tube swap in the TL helped *some* but not nearly enough.
The 60/120w heads/combos are the Tonelab guts...and IME MUCH better than the TL through the Atomic. I like the stombox additions, and the effects tweakability that and the TL add but tonally I dont think they are any better as is...through a speaker cab with celestions, I'm sure they improve markedly.
The DA5 is the real surprise...absolutely a killer little tonebox..ALOT of fun, and unlike the other Valvetronix amps, ALL the models sound really good. It has no tube so it's a little fizzy on top and lacks warmth but it makes up for it in speed of attack (there is no "sag" or slower response), and requires little to no tweaking. I lterally can get great tones by just plugging in, setting the tone control at 1-2 oclock, and EVERY model will sound really good. In fact some of the DA5s models sound much better and more authentic than the VTs versions...Soldano, Marshall TSL, Bassman and the Dumble overdrive for example. Its the perfect practice/bedroom amp. It sounds good at really low volumes, and pretty decent at higher volumes..and its a loud 5 watts with great projection.
I have some clips up at
www.soundclick.com/litrtrdnck. the first 5 or so clips at the top of the page.
The only issues i have had with them is reliability...my 50 died after a month, and my 30 got squirelly too..a couple of guys I know locally also had theirs die on them.they had a very high failure rate for a couple of years...but apparently reliability has been greatly improved and I've had no issues with my Da5 and AD15.
so IMO, unless you need tons of watts or the most versatility with effects combos and patch storage, grab a 15w or 50w "silverface" combo.