Saw the show last night. It's not terrible by any means. It's got a pretty decent score that I'll look forward to owning, where divorcing it from an actual performance might be of benefit - there are a few too many songs treading over the whole "what if???" theme (particularly in the second act) and I'm not actually a big fan of Here I Go or Always Starting Over which seem to be the big "fan favourites", but I very much enjoyed the opening and Lucas's song about Manhattan, for instance.
While the narrative is kept flowing nicely with all the movement all the time and I liked the set design a lot, there's a lot of choreography for choreography's sake - people twirling on the spot and leaning around a bit for no apparent reason. It's a style of choreography that's irritated me since I first remember encountering it in Andy Blankenbuehler's work on DESPERATELY SEEKING SUSAN in London - I'm not sure what else they would have had the ensemble do here, as they're so superfluous to the show overall, but it irritated me a bit to see.
Idina Menzel is fine - she's not one of my favourite actresses (I can't stand the handwringing she does!) but she's got a good set of pipes on her and she plays the part decently. I think it's unfortunate that Beth's storyline is fairly flat emotionally compared to Liz's - I don't feel like we get enough of a sense of the good things that Beth's career brings her as the show focuses so much on how detrimental it is to her friendships and overall happiness, and so Liz's life seems much more engaging and also moving (no, one short scene magically mending a potential divorce because "it'll make me sad" does not make Beth an emotionally sympathetic person!). If Anthony Rapp weren't playing Lucas quite so needy (although I guess that's partly how he's written) perhaps I would feel a bit differently about that storyline - I suspect that so much of it is based around Beth being placed in unhappy situations that it wouldn't improve with different actors in either the Lucas or Stephen roles (I think Jerry Dixon's fine, incidentally - it's just curiosity as to whether changing the actors would make a difference).
LaChanze is marvellous, incidentally.
As a Brit, some of the humour was a little America-centric but not unintelligably so.
Mixed reviews don't mean that a show is absolutely terrible. There's plenty to enjoy in IF/THEN. It's just not out-and-out brilliant. Idina's name should help it sell for a while, at least - and that's more than NEXT TO NORMAL had.
I did prefer the show when it was called SLIDING DOORS and starred Gwyneth Paltrow back in the 90s, but that's neither here nor there
