Gains that no one will notice and the VAST majority of consumers will not care about, or even know exist in the slightest way. Why would Samsung even go down this path and waste their resources on something that is only a vague issue on paper?
Even though I'm currently using an ip6+ I can honestly say that subjectively the Note 4 has a MUCH better screen. Not only in fitting more elements on screen, but I also get odd banding issues at times in the ip6. The note 4 was brighter in sunlight and had more accurate colors. Once again just subjective, but I think the displaymate review speaks for itself. That's not to say the ip6+ display isn't glorious, it is.
It's just splitting hairs anyhow. Why people spend so much time splitting hairs on such minutiae is beyond me, especially minutiae that just isn't noticeable to the naked eye and not applicable to anything and not noticed by any of the consumers who will buy the product.
More accuate colors? Thats where your lying cause i highly doubt you kept your note 4 in basic mode when it is only then it has more accurate colors then the 6 Plus . And also there is no difference really at all in sharpness between the 6 Plus and Note 4 , anyone who says they notice a difference in pixel sharpness is just lying. The notion that the note 4 has a "much better " display is complete nonsense considering the 6 Plus comes extremely close to Note 4 DisplayMates testing in between the both
366 PPI when viewing red/blue content on the Note 4 is noticeable bro, and offers less sharpness then the 6 Plus when your reading red/bluish content, thats where your wrong, cause one consumer can see and tell the difference
And odd banding issues? That seems like it is a defect or so on your part because i havent experienced any banding at all, thats weird
note 4 can only go brighter then the 6 Plus in one case, only in sunlight. I like to have my brightness up really high when im also not outdoors and so the 6 Plus has a brightness advantage there
And i also think the 6 Plus display is better due to one simple mere fact, the LCD display in the 6 Plus wont suffer permanent screen burn in issues that is prevelant and a big issue with all OLED displays after you own it for a little while (been through 4 galaxy s4's and they all had got permanent screen burn in due to OLED technology and that being a disadvantage for OLED Tech)
(Theres already people complaining and Erica Griffin included that their brand new Nexus 6's have already suffered permanent screen burn in, im pretty scared to own a device with a OLED display after all my S4's in the past have all each experienced this issue, even with me being a nut and keeping the brightness low always and making sure im not on one screen for too long and that i would run color changing videos for a bit to "even" out the display in attempt to prevent the burn in from occuring and it still happened, even after being that concious about my display and making strong efforts to try and prevent burn in, with my 6 Plus i have no worries at all even at maximum brightness that i will suffer any burn in at all, its a sigh of relief honestly)
Both are top notch but to me the pros of the 6 Plus display outweigh the pros of the Note 4 display and the cons of OLED displays and how they can be burned in easily and permanently throws me off too a ton, to each of their own, but the fact that you said that the note 4 is "much better" is just laughable and totally wrong too
The fact that you said "this is only a vague issue on paper" is already instantenously wrong, they already have stated that the Note 4 is not the most perfect optimal display for VR because of its Pentile effect with red and blue subpixels being rendered at 366 PPI compared to 524 PPI for white and green subpixels
So there is one issue already that isnt "on paper" even though most people arent and wont use VR yet