I have the ART Pro Channel mic-pre (the single channel, and not the Gold version). I got this over the Gold because I had heard this was better for vox. While I cant argue that one way or the other cuz i've not used the GOld, I can say that i like this mic-pre because it gives you alot of control, brings some tube warmth, and is very transparent. thats what i wanted to start with, transparency in sound. ($300 US)
I had originally started with a basic presonus tubepre single channel ($100 US). , which i actually really like. I couldnt stand the presonus comp, returned that right away. it really colored the sound, and not in a good way. but the tube pre brings some nice warmth to the sound, and I still use it and still have friends borrowing it to track things like bass.
I recently purchased the Joemeek OneQ ($650 US), interested in catching trying something that adds a more "classic" sound to round out the transparent ART piece. I must say, i really like the amount of control it gives. while its not a tube mic-pre, it brigns some interesting color to tracks. I love what it did for my bass tracks. I'm just going in DI through the joemeek and it added thickness and warmth and just overall goodness. On the vox i really like it too, but i honestly havent experimented enough with it yet to really discuss thoroughly.
also, take all this with a grain of salt, as i've never used $2000 Avalon and Neve's.