Personally, I haven't had any problems with the Valvetronix amps. I still own an AD50VT 212 and after selling one, I wound up getting another. It's a great amp and alot of fun. Although the VTX series are an awesome choice, 120 watts IS loud.
I'm going to toss a wrench into this now...
I recently picked up a Line 6 Spider IV and have had it now for over a month.
The tones and the FEEL are better than any modeler I've played so far, including the Vox. Line 6 has been releasing updates to the firmware too so it just keeps sounding better and better.
Seriously, alot of folks frown on the Spiders, but the new Spider IV's are unlike any other modeler I've played, including the Vox. Again, what suprised me the most about the Spider is the FEEL of the amp...very tubelike, warm and none of that digital harshness like on some other amps.
Guitars: 2003 and 2004 American series strats, Squier Classic Vibe 50's Strat, Squier Deluxe Strat.
Amps: Line 6 Spider IV 120, Vox AD50VT 212, and Peavey Transtube Bandit 112.
Pedals: Digitech Bad Monkey.