Here is an HDR picture taken with my A55. It really works to get the shot when a single shot wouldn't.
Good: It works, even in a scene with many people. A couple of the people here can be seen in double images but most look fine. I don't even mind the double images, as it looks cool and it would be that or nothing.
Bad: Why are there several inanimate objects on the right side of the frame that seem to have moved?