I've gone every year since the show moved to S.M., and last year seemed the smallest (attendance-wise) so far. Well I think that last year must have been an aberration, because just now I went to book a room for this year (thinking I was doing it well in advance), and many of the places I've stayed before are already booked full; and a couple of the nicer places that do have rooms -I'm talkin' to you Holiday Inn!-, have jacked their rates way up in expectation of a capacity weekend I guess. For comparison, last year plenty of rooms were available still a week before the show. If you are planning to go but haven't booked yet I recommend you get on it.
I went the first year and probably wouldnt go back even if I had the money. Its twice as far and half as good and Paso Robles.