Sony a57 High ISO stills & Video – Noisy sensor ?!

Hi, I have been looking at Sony's a57 and the Canon 650d. For me the Sony looked as the best choise in part because of it's fast and precise AF in video-mode and it's low noise level (no mirror).

For the most part I shoot stills and video under light conditions that require ISO 1600 – 3200 and when comparing pictures from the two cameras using tools like dpreview's, I find them to be about equal.

The strange thing though, is that I also see an alarming number of a57 users on the net, describing how their a57 gives them terrible noisy pictures, when they take high iso pictures. Comments that I do not see from Canon 650d users.

Any comments, from other a57 users ?