There are a lot more household names on there than there used to be. I did a count, and being the relatively musically sheltered person I am, I recognized about 20 names of guitarists that I would have known regardless of the forums, YouTube, etc. And some of them are pretty bigguns, obviously. It's a good thing.
Far as how many use the amp sims...well, we know some of the ones at the top of the list don't. Lifeson uses his Lerxst and Mark V heads. Petrucci has his Marks. Vai uses amps, but sometimes the models. But that's not really the point. Point is, they ARE using it. If it's good enough for them, it's good enough for little old me. Best buy I've recently made, gear-wise.