I loved the production overall, but sitting in the Upper Circle meant I could not hear very distinctly some of the dialogue, in particular Sir Toby Belch.
I felt Mark Rylance was bit OTT at times as Olivia, in playing up to comedy effects, and playing for laughs in a part that I didn't think should lend itself so readily to comedy, at times he made her seem almost more like a Pantomime dame than a genuine character, which stripped away the dignity of the role - it is for the comic roles to provide a contrast and relief from her high seriousness.
Stephen Fry was just Stephen Fry doing Malvolio, I have seen better amateur performances, he could have been so much more affected, effete and self-obsessed.
The twins were absolutely fantastic, and the Count Orsino - brilliant!
Also I don't just get the thing about all male casts just because that's how they did it in the 16th/17th centuries, Shakespeare's conception of those women roles was as fully-rounded female characters not as men playing women.