I saw it years ago and remember being disappointed, to the point that I could barely remember any of it later. But after reading Peter Bogdanovich's interview with Welles about the film and how the studio mangled it, I wanted to see it again.
Wow. I couldn't agree with Welles more. The conventional, telegraphic musical score almost destroys it -- especially the hall-of-mirrors sequence. And the opening reel in Central Park (which Welles had wanted heavily cut) was embarrassing; poorly dubbed and edited. I sense the film as a whole was supposed to have a mysterious, bizarre atmosphere, but they tried to make it look more like a standard-issue noir. I would've loved to see that funhouse sequence (I guess that was destroyed or lost?)
That being said, although I'm sure Lady from Shanghai was a far better film in Welles' original edit, I'm not entirely convinced it would have been as great as Kane or as our imagined concept of the original Ambersons. I found Welles' performance stiff and unconvincing, especially the brogue. Somehow I just don't see him as a naive follower; his big, unmistakable presence defeats that. But I thought Everett Sloane was marvellous -- playing a character the exact opposite of Bernstein!
I guess we'll never truly know, though...
What are your thoughts on Lady?