I was in the front orchestra, and didn't see any notables, but a lot of production people taking notes. I wasn't looking too hard though, so maybe someone can report differently.
The orchestra sounded wonderful. They got a well deserved focus of applause at the end, even more than usual. It sounded very rich & full, which is unfortunately rare nowadays, especially in Sondheim shows. The orchestrations didn't seem to be reduced at all from what I could tell, and there was a nice balance in the sound levels between performer and pit, amazingly so for the 1st preview.
I'm not musically inclined enough to say if Elaine Paige took it down a step or not, but I would hazard a guess she didn't. She really does belt it out at the end, after 'whatever happened to her,' she lets loose. I heard some negative comments about her at intermission, but I thought she was perfectly fine, other than the lyric flub where she repeated one verse twice. She sounded incredibly powerful on the last notes, and got a lot of applause. Maybe she could have brought more character to it, but I think vocally she was very strong.
I loved Raines, and his voice really carried through the theatre well in the baritone. I thought it was a nice change to have a Ben that sounded so rich vocally. 'The Road I Didn't Take' was the only part I was a bit let down. Maybe not let down though, since I've never really liked that song that much in general, but it wasn't really a moment where he could let his tone shine through, so it felt sort of claustrophobic and he wasn't able to get out. But otherwise, I was really impressed by him, and I think he made Ben a very layered and interesting character, though I personally found him (Ben) completely unlikeable! I always think it's interesting to hear people in discussion cast blame on one character in 'Follies' or another for being the domino to ruin everything, when really it's the totality of the circumstances that I think are the cause. But here, I really was a bit angered at Ben's passiveness.
"Are you sorry for civilization? I am sorry for it too." ~Coast of Utopia: Shipwreck