I also saw this last night and am a bit more measured in my response to the show. I'm still chewing on it (which is usually a good sign for me), so these thoughts might not be fully cohesive.
First, it wasn't nearly as loud as the early reports had indicated. So it seems like they're working that out. There are some gunshots in the prologue/overture that were jarring, but the actual musical sound design was on the louder side but not unbearable in any way (to me at least). That said, I think there are still some big sound issues to sort out. I particularly struggled with understanding Ali Louis Bourzgui. He sounded mealy mouthed to me, and I'm not sure if it's a mixing issue or if he's bad at enunciating. My instinct is that it's the former. But either way, I lost a lot of his lyrics.
The overall design and direction was, at times brilliant, and at other times a bit perplexing. They're going for a very retro feel that, by and large, works, but sometimes feels really cheap. And the pacing of and transitions between certain songs and scenes still needs some work, I think. The first act was interesting because the whole thing felt like one long overture that culminated in the rapturous release of Pinball Wizard. The second act felt much more uneven.
In terms of individual numbers, there were some standouts. Pinball Wizard was, of course, thrilling. I also really liked Smash the Mirror and the I'm Free sequences. I thought Fiddle About was staged effectively -- creepy but not crossing any 21st century boundaries.
21 was a little confusing because Allison Luff (brilliant as she is) didn't read young enough for that particular scene. A slight makeup/hair/wardrobe adjustment would go a long way there. I didn't find Acid Queen terribly successful. It wasn't clear what message the direction was trying to convey from that scene in particular. I also lost the narrative thread a bit from the introduction of Sally Simpson through to Tommy's rejection of his fame/celebrity.
These are all quibbles though. Overall, I found the show effective, and I enjoyed the ride. I went into the show only knowing the concept album -- I'd never seen the musical and haven't spent much time with the original cast album. So I didn't realize just how operatic the score is -- I kind of expected more standalone songs/scenes. But the constant forward motion was ultimately really effective -- especially in the first act.
I'll be interested to see the critical reaction to the piece. I know it got raves in Chicago, but I'm expecting a somewhat more mixed reaction from New York critics. At the same time, the experience is thrilling enough overall that I won't be surprised if there are, in fact, raves. I guess we'll see in a few weeks!