[AT&T Samsung Galaxy S7 Guides, News, & Discussion] najoor:
My experience with this root method

Let me first start by thanking the people who made this root happen, in particular [MENTION=631273]Chainfire[/MENTION], [MENTION=5028474]princecomsy[/MENTION], and [MENTION=4911585]br3w3r[/MENTION]. Perfect or not, developing these methods against the odds takes a lot of time and dedication and we all owe them for that. I also want to say that I have about 10 different android devices all of which are rooted, even when it meant that the warranty would become void, so I am a true root-lover if you may.

I started by backing up my data and completely erasing my S7 edge (recovery -> wipe cash and data). Then followed the steps carefully and all worked as promised. However, the outcome was a laggy and buggy system., even after all the fixes and tweaks were applied.

The biggest problem is the engineering kernel that should be flashed for this root to work. By default, this kernel runs the processor at the maximum clock frequency and you may or may not notice it depending on your usage and the amount of heat it produces. The only way to fix that is to install a kernel tweaking software and change the CPU governor from performance to interactive or ondemand. That however is not going to solve all of your problems because, while the heating and battery issues are mitigated, the phone becomes laggy. This is evident when you try to scroll down a long list. For example, open the app menu in settings and show all the apps including system apps. Then scroll up and down and you will see clear stuttering which is very unusual for the processor in this phone. Same results are observed if you browse a long internet page. The fix is probably to tweak the governor parameters but that is really a time consuming process that was honestly fun only the first couple of times I did it with my other phones. I don't have that kind of patience anymore.

The injection of supersu seems to be buggy too. Try for example to disable any app with android's pm command (as root) and you will get an error message (I have already reported that in this thread). Also some applications such as Terminal Emulator now take forever to start. There are performance issues here and there and sometimes it is hard to tell if it is because of the kernel or the root method.

Another indication is that the Antutu score after root went from 135K down to about 110K. That is a 20% hit that I am not willing to live with. I can already get that kind of score from my old Nexus 6.

You cannot touch or modify this kernel either because then the trust chain will break and your phone will refuse to boot up. Just for giggles I flashed supersu 2.76 on top of the already rooted system (in hope of fixing the su injection) using flashfire. In the middle of doing it I suddenly realized that this supersu will patch the kernel and I was 99% sure it would knock my knox flag. What happened was that the phone gave a message to the effect of: this phone will not boot with a modified system, take it to an AT&T center to fix it. I then re-flashed the engineering kernel and to my surprise the knox flag was still 0. My guess is that if you flash a non-engineering kernel after you root the phone will not boot up either because of of dm-verity check.

I am not gonna talk about how android pay and Samsung pay are not working because I guess everyone knows that.

So for the first time in my android life, I went back to unrooted stock. Sorry, but this root method is not working for me.

So in case you are wondering about the alternative, I strongly suggest that you flash the unlocked ROM (935U) posted in the forum. It will bring your system to the unmodified state as if nothing ever happened (Binary: official, Status: official, Knox: 0). It is smooth as butter and has no carrier bloat. It gives you additional advantages and perks such as tethering with no restriction. The only thing it doesn't have is ATT-specific services like VOLTE and video calling, which honestly aren't worth much when offered by ATT. Then ask yourself why you need root and consider other ways of accomplishing the same goals. For example, instead of using Adaway, use Crystal Adblock which nicely integrates within the Samsung browser, or if you cannot disable an app or a service such as Software update, use Package Disabler Pro or something like that and you will be set.