We went to Studios on a Star Wars weekend last June. We actually did it on purpose, since we had several fans in the group. I did not notice any crowding problems. THe only place that seemed effected was over by Star Tours. Fantasmic seemed to fill up a little fast, though.
I'd go if I were you. along with the normal characters, you also get Storm Troopers on top of buildings etc.
Just be sure to plan ahead for Fantasmic, or do the dinner deal with mama melroses, so you have guaranteed seats.