I saw both the London take on the story of MM and the Broadway take.
IMO the London version was much better than the Broadway version, which was atrociously bad. The London show was much more ambitious, with a huge 'but'. It struck me as an attempt to make a musical about MM, but to ripoff Evita as much as possible in the process. The thing I most remember was that there was a Che Guevara type character who, as I recall, played 'the camera',never part of the story, but always commenting on it. The concept was not bad, and the production looked expensive, highly professional, etc.; but I kept wondering when the camera was going to break into one of Che's songs. It just was derivative. II would also point out that the actor playing the camera made a much stronger impression than the actress playing MM,which was not good. Bottom line: I was never bored, frequently entertained, and thought it might have been a hit had it opened BEFORE Evita.
The Broadway version was a mess, with all kinds of derivative characters playing roles that had nothing to do with the story. There were -- I think -- three people playing gossip columnists, commenting on the goings on; two -- I think -- who played fans involve with MM, and a third set, but I cant remember what they were. Her husbands??? The only thing I remember with even remote fondness was the number trying to play homage to Diamonds Are A Girl's Best Friend. As I recall, Allyson Reed was fine as MM, and looked great in a fire engine red spangly dress during the Diamonds homage. But what a mess. i still find it hard to believe that anyone would have invested in the show in the first place, since the score was lousy and the book totally lame.
Anyone who remembers this with fondness either didn't actually see it OR it was the first show they ever saw (which creates memories regardless of quality issues) or was on drugs the night of the performance. It was a lot of money spent on a hopeless mess.