Has anyone met Andrew Robinson or Alexander Siddig? I'd really like to know whether they're jerks or not.
They're not jerks. I still associate Robinson with being Scorpio in Dirty Harry (yeah, showing my age here) but he's so polite and cuddly it's unbelievable. Sid's a nice guy and remembered who I was after a five year gap - that's pretty good going.
I have to say I've had no real bad experiences with any Trek folks I've met either as an attendee or as a fellow guest. Maybe this is because I haven't met the wrong ones, and maybe it's because I've tended to meet them at smaller fan-run UK cons rather than big expos.
Um... Lemme think of the variations...
Walter (and I last met him in the mid-noughties) could be distant and surly at one con and dancing on the tables (literally, I've seen him do that) the next. I'm told it depends on whether his wife is wife him or not. (I'm much the same - I'm a lot happier if my wife is wife me)
Jennifer Lien is kind of a martyr, trapped between a phobia of crowds and a desire to give something to the fans. You have to admire her dedication to doing something (cons) that obviously makes her uncomfortable. She'd never be rude but she might shy away from you...
Everybody else I've met from Trek ranges from polite and professional (Rene, for example, or John De Lancie) to an outright bundle of fun (Max Grodenchik, Garrett Wang, Marina, etc)