There has be a difference between units, because while I don't have DX to compare it to, I can attest that my S3 is freakin' blinding with the brightness turned all the way up. I generally keep mine at about 35-40%...and that's not to save battery, that's because that's where it is comfortable to look at.
I do agree that auto-brightness implementation and the default browser dimming are both awful. Luckily, I have no interest in using auto-brightness, and the browser thing was an easy fix in the settings.