I have been using Nikon for years but got interested in Sony after a friend showed me some pictures he took with Panorama.
I tested a55 and even though its now available for $499, i though it was worth going for a57. I just bought yesterday at a local Bestbuy and was surprised as the launch date was April 22 but it was avail in store on 18th & at $40 discount after you checkout
-a57 has same body size as a65 so hand fits well. On a55 felt small with pinky hanging
-Some great features that are unique to Sony: Panorama, auto smile, 10-12 frames per second -Looking to test Auto portrait that creates a copy that crops using rules of 1/3s. Although read that it cant be used in RAW mode (bit of bummer)
Coming from Nikon, its taking a bit getting used to. The menu is not the best but works
At first when you place your eye on viewfinder, its a bit of delay and getting used to. Also its quite bright in Sunny outside. At one point while testing at Sony store, I thought something was wrong but then realized i had put aperture of 1.8 which was too much light and couldnt see anything.
I will update after using a bit.
Update: 1. Pictures come out great. In some cases I have noticed that the white balance between pictures taken at same place is quite different. Havent figured it out yet why. Some pictures came out right while others are blueish. 2. A bit of bummer, I knew about it: I like to take pictures in RAW - none of cool features HDR, portrait etc are avail in RAW mode. 3. I read that the contrast and colors are much nicer + low light is better in a57 vs a65 - Mainly because of JPEG processing improvements. So again if you use RAW mode the software would help.