Excellent and engaging first half hour devolves into verbose, stagey, self-indulgent faff. Throwaway violence that's over too quickly, poorly written female characters, tiresome longeurs between set-pieces and a strange lack of tension.
On the other hand, the performances were uniformly great, though the bad guys felt like panto villains. Also well shot and scored, parts of it felt genuinely Nero / Leone. I found it mostly entertaining, but as a long-time QT fan was a little disappointed at the hollowness of it all.