Saw this tonight as well, and I second Bettyboy's statement about the first five rows. The choreography is such an integral part of the experience you want to be further back to get the whole picture. The Music Box is small for a show of this scale, you won't miss anything at all by sitting upstairs.
That said, I found more to admire than to enjoy. Audra and Brandon Victor Dixon fare best because they are given actual scenes. Their relationship is beautifully played, with room to breathe. The songs within their scenes grow naturally from the situations, and you care about what happens to them through the evening. That is in contrast to most of the story-telling contained in the show--because most of the rest of the story-telling feels like a lecture. A lecture accompanied by world-class tap-dancing to distract you from the amount of information you are being fed about people you do not meet, situations you do not see, and stories that are never dramatized. Because so much is being TOLD to you by the actors, the show keeps the audience at arm's length throughout, and it is only through the sheer talent of the performers themselves that we are occasionally allowed to feel anything.
Individual numbers in Act One were uniformly terrific, and if they had been interrupted less by Ken Burns-style factoids, they would have landed even better. The first 20 minutes of Act Two were thrilling for me beyond anything that Act One offered. One dazzling moment after another, coupled with narrative thrust, even as the various relationships felt the strain of the success of the "Shuffle Along" phenomenon they had created (against all odds) in Act One. Then come a series of catharsis numbers, preceded by quite a few scenes that devolved into people yelling at one another because of real or imagined slights. Billy Porter lands his number with the soul-twisting. agonized vocals that he does so well, and Audra--well, Audra just breaks your heart with "Memories of You". The half in black-face number that Stokes is given works better in theory than in action. It's a lot of effort attempting to flesh out an idea that is said perfectly in the first image of the number: he walks onto the stage for what has always been a two-man act, and on the other side of the stage is a spotlight with no one in it. The number is him trying hard to fill both spotlights, full well knowing it's a lost cause. Try as he might, there's just not that much to play, and we start to feel the desperation of the performer rather than the character. The audience response to this number was the most tepid of the night.
The penultimate number with Brooks as the critic telling them all they will become footnotes in history suffers from the same problem--once he's said it, there's nothing left to do but say it louder while the principals protest their fate and try to make their case. It's potent and it's right, but it has nowhere to go, so it outlives its usefulness.
While there is much to enjoy because of the generous and amazing talent assembled, I was seldom moved or involved. A show shouldn't tell me so many times how important its story is. Just show me more. Lecture me less.