My reason for returning this defective S6...

My note 4 is brighter has a brighter display than my s6. I hate s6.

I traded my s6 in for the Note 4 since Tmobile deep discounting them now and I can also say the screen on my Note 4 is a lot brighter than the S6.

I actually dig the bigger screen too. At first I always thought the Note 4 Iphone 6plus was too big but it still fits in my pocket just fine and love the bigger screen when typing too.
 
This. Coming from an iPhone I never messed with screen brightness and just let it handle things. However, I keep my screen brightness on the S6 down to ~10-15% and it's plenty bright for me indoors. The iPhone just got TOO dim. When I'm outside I simply swipe down to quick settings and adjust as needed. I'd like to think I'm smarter than my phone and control simple and easy to access things like that myself.