civil-case reversal rates are much higher than the U.S. (http://scholar.google.com/scholar?cluster=11027117874758072323), I still can't find anything on criminal cases though. komponisto said about 1/3, any cite on that?

It was a remark by Amanda Knox's attorney, Luciano Ghirga. I can't remember where offhand.

One would expect the rate to be much higher than in the U.S. simply due to the rules of the game: unlike the U.S., Italian courts at the first level of appeal are allowed to reexamine the facts of the case, instead of merely ruling on whether procedure was correctly followed.