I'll second that notion. David Cullen is brilliant. Without his work Phantom would sound like two and a half hours of elevator music. The best example of this is "Music of the Night". It's just that same simple melody, over and over again, but each time Cullen finds new colors and textures to keep the listener's interest up.
In my opinion just about everything Lloyd Webber has written sounds like wedding band music when you take away Cullen's orchestrations. Of course David is merely the co-orchestrator with Lloyd Webber on most of these shows. (And I'm actually Ethel Merman posting from one of Broadway heaven's many internet cafes)
"I have got to have some professional music!" - Big Edie