I must say I'm not surprised that some people don't like her voice.
I'm going to say right now that I'm not one of them because I was quite frankly blown away right when I heard the CD and she's even more amazing live.
I think what some people didn't like, or didn't understand, is that her character is, being the diva that she is, a caricature of many female parts in the musical theatre and as such, she sometimes emphasizes certain things and overdoes some parts in songs.
However, and to me it's the main reason she deserved the Tony more than any other actress nominated this year, she manages to be outrageous vocally without ever sounding bad in any of the many repertoires, ranges and genres she tackles... all this while being hillarious!
Sure it's a comedy but I don't see any part for featured actress, even dramatic parts, that were as challenging vocally and acting wise as hers this season.
just my 2 cents, of course...
"What book of rules says that theatre exists only within some ugly buildings crowded into one square-mile of New York City? Wherever there's magic and make-believe and an audience, there's theatre..."