I've skied up there. Yeah, it's overrun with slednecks and their oily blue clouds and a cat skiing operation. You could probably ride on the packed road or some of the more heavily used branches but it would get pretty soft and deep off any of the well packed routes. It's a large basin, but if your limited to the well packed routes you'll only be able to access a small portion of it.
It's better on skis although I don't really ski there anymore. Too many people, too much noise, too much two stroke carcinogens in the air, too much clueless behavior above you.
BUT... if none of that is an issue for you what the hell, go for it.
I rode to the Jones Pass saddle along the main cat trail last Monday. It was ride-able 3/4 of the way up and then turned into a hike. Was a lot of fun, but other than the well packed trails it was too punchy to explore around. The descent was pretty awesome and fast.
After Jones, I went up Butler and it was much more of a hike a bike due to the grade. Downhill was pretty awesome as well.
Only saw a couple of snowmobiles since it was a week day.