As a professional (European) musician I strongly disagree with the title of the topic. One important thing that is being overlooked is that orchestras simply evolve as time goes by. The LSO of today isn't the LSO of let's say the early 80's. Not worse, not better, different. The same goes for Hollywood players, who are equally good 'orchestral' musicians as all the rest. Most of those people get drafted from the Symphony orchestras of southern california if I'm correct (LA phil, Pasadena symphony, etc..) My favorite sounding orchestras are, in no partical order, the hollywood studio players of the 80's (E.T. for example), New York phil from the 60's, Cleveland orchestra under bernstein and the one orchestra which stays true to its sound, the Vienna Philharmonic. And for your information, when the LSO records for something like a film score, more than ever these days, players from other London orchestras and free lancing players also play along, mostly in the brass section. And that's why I believe they don't sound as 'homogeneous' as they used to, too much different styles of sound mixed together. I'll take Hollywood over London at this point.