So after a week of having it, I haven't found much to dislike about the update. It seriously makes the S6 feel like a new machine. This is also coming from someone who got the S6 as a "had to" and seriously disliked its
Battery saving modes are impressive. Standard non-saving mode, is a little better while in standby, and running core apps. I find that its a pinch more power hungry when doing video and camera work than it was. While in mid power saving mode, I get nearly double the run time that I did before. Almost feels like I have a bigger battery than I do in it. Max Save makes a good "work" profile when ever I am in a point that I need to limit phone and app access.
The new camera software is easily twice as fast as the last one or even most third party camera apps.
I use google messages as well as the google keyboard, so I'm not having any issues with the stock messages or keyboard apps.
To the person that was complaining on the background of the stock messenger, I'm pretty sure you can change the background in the Samsung Themes feature.
I LOVE the native reply feature in nougat. I can reply to facebook posts, texts, FB messenger texts, nearly anything with out going into the standard app. Very much a win.
Phone and contacts apps are much crisper and flow a ton better.
Native Blue Light filter is excellent.
I'm not sure if anyone can confirm, but I believe the radios were improved upon as well.
My only gripe is to the drop down menu. I can't scroll left to right while it is "half down" like I used to. In order to see past the first six options I have to do a full pull down.