I'm a firm believer in these amps......so much so that I hope Vox comes out with an improved version. I was disappointed this year when I saw Vox didn't have a Valvetronix II.
I was a HUGE tube snob before. I'd given some Line 6's a chance, by owning Flextones, but I sold them and said I was done with modelers. Then, I got hooked onto the Vox heads, and love them. The combos aren't bad, but in order to go head to head with tube amps, you should use them with the same cabs you'd use with your tube amp. That's why I love the AD60VTH and AD120VTH blue grill heads. IMO, those are the ones to buy. Like Scott said, they love Vintage 30 4-12 cabs more than anything else. It allows the Marshall models to sound more realistic. And speaking of Marshall tones, the Marshall models aren't always the best ones to use. Like Stratdeluxer97 says, try the Bassman 4-10 model along with an OD model, and crank it up. He A'B'd it with his ACTUAL PLEXI and got his Vox to sound almost the same!
And he uses the Vox live, when he even owns a vintage Fender Pro Reverb and 50W plexi with a point to point board! For someone that owns classic amps to rely on the Vox as a gigging amp speaks volumes about it.
This isn't an amp that will floor you when trying it in the store, with their junky speakers, and guitars strung with 9's and stock pickups. You need to take it home, listen to it with your guitars, and plug it into a high quality cab.
Then, you'll realize it's potential. It's a fun amp. From Blackface to Tweed, to Marshall, to Dual Recto? For $400?