It performs GREAT! The heat sink works well for not letting things get too hot (unlike say a vintage Matchless or something) and I have found that the half power switch comes in real handy when you have to be a little quieter but still want to get the power tubes rocking. Also, you can assign the FX loop as an additional master to control things if you like. I haven't had the need to do that yet though.
Of course, everyone at the company is super helpful and the amp is built like a tank.
Well, that is hard to answer due to the fact that it is a 6V6 based amp....But having said that, I have gotten some great sounds that get into that Marshall 18 watt vibe with the amp at 1/2 power with a Celestion Blue 1x12. I have also gotten more of a JTM vibe by going into the Low Input (full power and Celestion Annv G12H 2x12) and using a few different of treble boosters I have.
The "voxey" part of amp comes with the "Class A" design...it can get some of that spongy sound that say, the AC30 is known for.
It's pretty shocking how flexible the amp is...between the two channels, power switching, and also the Focus control can do quite a bit as well.
I asked a question about the Venus 6 a while ago, and also got surprisingly little feedback. I also thought the clean channel was great when I tried the 1x12 combo in a shop, but channel 1 sounded a bit brittle to me, and I didn't have a chance to turn it up to find out if that goes away. I also find Rivera's video demos to sound kind of brittle and sterile, and I've found none at all which show what a Strat sounds like through the amp. I was interested in the Quianna for a while, but again couldn't dial out that unpleasant hard edge to the lead tone, and found myself doing way too much knob twiddling to try to get the tone I wanted. These amps are supposed to be up there with the best, but so far I haven't been pursuaded. I also feel that if, like me, you like to control things from the guitar's volume pot, this is probably not the amp for you. I may be wrong though, (in fact I'd like to be wrong!), and would be interested to hear from anyone else.
I have actually talked to Paul Jr. about the videos. We were gonna do one that was more in the context I use it (more rootsy and classic rock, less hard rock)...I just hasn't panned out yet.
The gain on Ch 2 (Clean) is great. I use it more for the tweed-ish, low mid thing. With the notch pulled, you get some great blackface style cleans. Recently, I did a session using a mid-60s Fender XII and the Venus (I primarily use a the Venus 2x12 Cab with Celestion Blues in it) and it was a great Byrds/Petty sound for that song.
I use Channel 2 more (due to the style of stuff I am playing at the moment) than Ch 1...with the hi/lo inputs and available boost you again have a TON of range.
I really did find that once you get the vol up a little bit (nothing crazy, mind you) that harshness goes away. The Blues also do impart a great vibe to the sound as well. I found the Venus with the Annv G12H sounds really good once it gets worked in a bit.
At one point a friend and I working with a band on their latest record...and we called Rivera to try out the Venus 6 (just post NAMM 2007) and they brought down one of the first ones with a worked in 2x12 and I was sold...The Blues just took it to the next level to me.