Wow, was trying to decide between the Evo 3D and the SGS2, and that banding issue reported in the XDA thread would definitely keep me from pulling the trigger.
I have owned one now for a few weeks, and I can only complain about battery life. Moving from a Smartphone with win mobile, that lasted some 5 days with heavy use, down to 2 days on the Samsung SII is a lot of a fall for me who uses the phone just for working reasons and need to have it always on. Other than that, it is a pleasure to use. And the speed is awsome.
I've had the GS2 reboot on me once or twice in the last month but that's about it. I don't consider that an issue. This is by far the best Android phone I've used....period! And I have used a number of them. Gave up the Atrix for the GS2 and there are no regrets.