This is how I felt when I saw it like 5 years ago at The Geffen in LA. I was surprised to see it finally make it to nyc (again, I think, right?). A decent play with a decently compelling subject but the play itself just didn't move me as much as I'd expected and it wasn't as unique or memorable as I'd think it would need to be.
As for the running time... were you watching the clock from when the *play* started, rather than curtain time? Because almost all shows run 6-10 minutes longer than the advertised running time because almost all theater delay the start for getting people in their seats, and most intermissions seem to often run 2-4 minutes longer than advertised.