Judging from his measurements, the panel's traits seem almost identical to those of the Note 4, except for the increased PPI. Gamma is still slightly on the higher side (2.35), and maximum brightness displaying white is comparable to the Note 4's screen. It's strange because in some of the S6/Edge videos I saw the screen looked a lot brighter than previous AMOLED screens. For example, in MKBHD's preview (@4:58):
https://www.youtube.com/watch?v=TtLHiiXyERA#t=4m57s
The brightness slider is approx. at 20% and the screen looks quite bright. The whole preview looks to have been shot at that brightness (20%), which left me an impression that Samsung raised the brightness bar significantly compared to previous gen AMOLED.
Displaymate's numbers disagree with that impression and the S6's screen is about as bright as the Note 4's screen. So maybe the Note 4's display is better than I thought, or maybe MKBHD's S6 sample in the video was better than Displaymate's sample. (i.e. panel lottery)
In any case, all things considered, I have no doubt the S6/Edge's display will have the best smartphone display for consumers. And I think the reviews should give Samsung more credit for providing multiple color "profiles" that are for the most part accurate to industry standards, namely sRGB and Adobe RGB. No other OEMs even attempted to provide this advanced feature. (indeed it is kind of rare even on desktops)
Considering Android's non-existent color management + RAW support for camera in Lollipop, Samsung has another advantage here for users who may wish to venture outside sRGB for imaging.