The QHD SuperAMOLED on my Note 4 and on my friends S6 Edge are the two best displays I have ever seen.
Ever since the day in 2010 when I tried a I9000 Galaxy S in store I loved AMOLED. The Nokia N8 that I had later that year also, stunning AMOLED vs. the higher res 854x480 LCD TFT in my Xperia X10.
In 2011 got the Galaxy S2 and I was gobsmacked at how gorgeous it was, same with my S3....then Samsung brought the S4, with a stunning HD1080P SuperAMOLED, if I am not mistaken, Samsung at this point had reached a whole new level in AMOLED quality. I went from the S3 to the S4 and simply could not believe how sharp and crystal clear that panel was.
From the S4 up, Samsung became untouchable, the Note 3, S5, Note 4 etc...just pushed Samsung further and further ahead.
I must say though...I am a big fan of higher saturation, from the day I got the S2, I went to Screen Mode in every Samsung I got and set it to 'Dynamic', which is now known in the >2014 Samsungs as 'AMOLED cinema'. No other mode does it for me.