I'm using the Premium graphics setting at my LCD's native resolution with FSAA and AF enabled. It doesn't get more eye-candy-ish than this. (I have a Geforce 8800GT, so this is relatively easy for it.) It still feels like you're just floating out in space somewhere with nothing around for parsecs but this one little road and a few little random objects floating around. Yes, you get flashy effects, but they don't add atmosphere, they just add effects. It just feels like a visualizer versus that old beta with the bridge, sky, and etc actually feeling like you're somewhere.
It may not matter to everyone, but, personally, I'd love Audiosurf 3x more with such an atmosphere to it.
Well, putting aside the rest of the atmospheric elements for a moment, I am curious why skies are just absolutely not an option. I still think that would be an improvement. Heck, imagine if those flashy effects took place BEHIND the clouds (with maybe a few bits and pieces breaking through) using lighting effects and such to light up the clouds (well, mostly just basic transparency would be all that's needed I think.) It would be like you're in some sort of firestorm or something. IMO that would look a lot nicer even eye-candy-wise compared to the basic visualizer.