I thought it was good, not great. The '80s scenes definitely could (should) have been cut; the "Buffalo Soldiers" story is interesting enough, no far-fetched modern murder mystery was needed. And, honestly, I thought a great deal of it was a bit... confused. I believe Spike Lee tried to cover far too much -- the black soldiers, the Italian freedom fighters, the aforementioned '80s murder investigation -- in one movie.
Still, Lee's definitely a great director and it's a beautiful and often intense movie. And the acting, for the most part, is convincing. I definitely wouldn't recommend not watching it. I just thought it could have been better.