Over in an S3 thread, a poster explained that the radio in the S3 is more like an HTC than any of the previous Samsung's. It's because of the new chipset, etc... I understand that the GNEX doesn't have a good radio, but it apparently doesn't apply to the S3.
Also, every article about the display of the S3 mentions that the pentile display is way more advanced than anything else out there. Not as vibrant as RGB, but lasts longer.
I love my TB, but excuses that don't even apply aren't going to make me keep it. It's a little dated, not going to get ICS until Aug, and the battery life is less than desirable. Minor complaints, I know. But at least they're valid.
To each their own. IMO, the S3 seems to be a significant upgrade.