The Lyric Theatre was completely renovated, specifically for this production, and it looks absolutely gorgeous. A whole lot of Broadway theaters are in need of serious attention. The last time I was at the Majestic, for example, I was horrified at how run-down it looked, even with the dim lighting, which camoflauges a lot -- and that was like eight years ago. But it's not like they can just shut Phantom of the Opera down for three months or however long. The Lyric, on the other hand, has new everything -- including new carpet (covered in the play's "H" Hogwarts logo) AND new seats (the rows are so wide, y'all, at least where I was in the balcony, I couldn't believe it -- there is so much leg room that people can easily pass between them without anyone having to get up; IT'S AMAZING). There are two sets of surprisingly roomy bathrooms, three bars (Orchestra, Dress Circle, and gift-shop-adjacent), two walls of merch (Orchestra and Dress Circle), and a main floor "Refreshments" room.
There's a little room just past the main lobby area, which I'll call "The Patronus Room" (it's where the coat check is, and the elevator to Dress Circle). There's some lovely artwork with text from the play, including a great Ginny line, painted on the walls in the shapes of various Patronuses. Great for a photo op, of which I witnessed several.
AND something I didn't even SEE until the second night, because I originally thought the Patronus Room was the back of the theater -- just past that room is, well, the third bar, and then a HUGE (for a Broadway theater) Proper Gift Shop, with everything you can get from the little lobby merch stands, PLUS a whole bunch of Hogwarts/Gryffindor/Slytherin/Ravenclaw/H
I will also say that there is certain merch that is only put out for Part 2 because the artwork is a spoiler for That Thing at the end of Part 1. You can probably still get these items if you know they exist and ask for them. But they most definitely don't come out for display until you come back for Part 2, and I thought that was kind of awesome. I bought one of the souvenir programs, a really nice keychain, and a tote.
Most Broadway shows open the doors 10 or 15 minutes in advance at most, and then you have the truly stupid queuing an hour or two in advance, when EVERYBODY'S SEATS ARE ASSIGNED AND THIS IS IN NO WAY NECESSARY -- sorry, that's a thing that forever bugs me. So when I bought my tickets and they said to be there an hour early, I rolled my eyes like "psht, yeah right." While I'm sure you probably could get to the theater a few minutes before *this* show starts and still get to your seat in time, this play is doing things a little differently than the other shows. They *really are* opening the doors and letting people in an hour before curtain, and the queue moves pretty quickly, even with everyone having to go through bag checks and metal detectors. And there's plenty to look at and do for that hour. (For my part, I did a little pre-game the first night at a nearby Cold Stone Creamery - strawberry and peanut butter ice cream, a shout-out to Harry in POA - and wasn't *quite* there at the hour-to mark, but only a few minutes later and still had so much time to explore.)
There were several audience members in Hogwarts robes, so if you wanted to do that -- to get the proper, immersive experience -- you would most likely not be alone. Once you show your ticket and go through the metal detector, you can pretty much go anywhere you like, except to an area of the actual theater that you haven't bought a seat for (and obviously backstage). The bar is like pretty much any theater bar (sadly, they haven't gone all out with themed drinks, so no butterbeer, pumpkin juice or firewhiskey -- dropped ball, yo). The "Refreshments" area has all kinds of snacks -- mostly upscale, pre-packaged stuff, but there were some Milk Duds and Junior Mints and similar stuff, too -- and they have rows and rows of jelly beans, but they're not Bertie Bots. They also do bottled drinks (there IS pumpkin juice in here, but it's $9 for a pretty small plastic non-souvenir bottle), some little servings of ice cream, and a yummy slushee I tried on the second night. It was hella crowded in there.
When you enter the actual theater space, the usher checking your ticket will do so with a lighted wand, rather than a Muggle pocket flashlight, which I thought was a cool touch. And when you sit down (in your absurdly roomy row), you will see the stage set for King's Cross, with low lighting, and you will hear "train station" noise playing over the speakers, as if you're waiting for a train yourself. There are two separate "Showbills" (not Playbills) -- one for each play, but they're the same except for the title on the cover. I mean, I didn't do a word-for-word check, but they appear to be (with that one exception) exactly the same.
In slightly more specific, but not-too-spoilery terms, the acting is great pretty much across the board, though I had some age issues with the child actors. The trio are all great, as is Ginny (who got a huge round of applause after one especially badass moment in Part 1). The kid who plays Scorpius is AMAZING and steals every single scene he is in. He's a bit screamy at first, but I got used to him. The effects are jawdroppingly (yes, I did want to snog them) effective and seamless. Sometimes it's pretty basic (a swish of a cloak to suggest an object disappearing), other times I couldn't stop thinking about how in the heck they did it. There is one effect that happens like 8 times over the course of both plays, and I *NEVER* ceased boggling at its sorcery -- every time, my brain just went "WHAT." People are not exaggerating when they call this production a game-changer for Broadway and theater in general, particularly family-friendly fantasy stories.
I'd like to say that you don't have to be familiar with the HP series hitherto to enjoy the play, but the plot does still rely a huge amount on what happened in the novels. The Showbill does give a brief summary of each book, and an explanation of some of the characters and terms you might not know from cultural osmosis. And the characters themselves explain past events pretty well -- and it works, I think, because it's not the characters these things happened to doing the explaining. There's such a sense of history with all those events, major and minor, and it plays almost like these characters are quizzing each other on the details. For what it's worth, Paul Thornley (who plays Ron) said a friend of his who didn't know the books at all went to the play and loved it, so there's that.
A BIT MORE SPECIFIC (tread with caution if you haven't at least *read* the play)
Something overall about the play that I really love is how much of a love song it is to canon -- the canon as it is. Really the whole idea of a "set" canon. It's saying "what happened, happened, and you might not like all of it, but it's a fact and you can't change it." That's not a knock on fanfic at all, by the way, but there's definitely a thing in this post-canon fandom where people try to change the books, or come up with ways they could be improved, asking why couldn't this or that have happened instead (what if Neville had been The Chosen One instead? why couldn't Harry have lived with McGonagall instead of the Dursleys?), usually insisting it would have been so easy to write it this other way and the books would have been better because of it. Well, here we have two characters who try to change something they don't like, because they think they know better, and they just screw everything up. And the more they try to fix things, the more messed up it gets.
This play also ships OBHWF like there's No. Tomorrow. There's a moment in one of the train station scenes where the two couples just stand together and look lovingly at their (off stage) progeny, and it's almost nauseating(ly awesome). I love that, even in a world where Ron and Hermione never got together, Harry still married Ginny and Hermione didn't want anyone if she couldn't have Ron. Also, it seems like the whole school knows there's some "thing" between Ron and Hermione in that first altered timeline, because when Albus says Ron's name all the other students look at him like "you just f***ed up big time" and Hermione flies into a rage. And don't get me started on Darkest Timeline Ron and Hermione because THEY ARE MY EVERYTHING.
One complaint. Imogen Heap did the music, which was lovely, but there was not one solitary "Mmmm, whatcha say" moment in the whole play, which was a missed opportunity.
I want to squee so hard about specifics, but I'd better not. :P (I will, however, happily answer any question I can, for those who are curious.)