[Ascend Mate 7 General] blackinfinity:
I was able to update from C900B331 to 522 full version. All data intact, installation went good.

Observervations. I have tried nova launcher, google now launcher, apex launcher all these did give a lot of lag some times, the gui would freeze sometimes for one second or 2, sluggish animations and scrolling in apps and chrome.

Solution: Do not use 3rd party laucher even though I myself like some of the functions in nova and apex and google now etc, I really recommend using Huawei Launcher now, things have changed a lot, on lollipop 3rd party launchers was faster but on this marshmallow it is clear to me the Huawei stanard launcher is a lot faster and more optimized to the hardware, it is a lot faster and smoother.

Please consider I have set 0.5x in animation speed in developer options and force GPU render in 2D apps, these setting make animations more demanding on the phone and Huawei launcher handle the speed a l lot better.

The only thing that is not good with Huawei launcher is the folders, I do not like those folders I like nova launcher folder better, I do not need them to come up in full screen it is stupid and ugly and not as fast...

Scroll speed was a lot faster in huawei launcher.

I have only used Marshmallow for about 12 hours, and it was in the last hours I did realize that 3rd party launchers have problem with this device (even google now launcher)

Multi tasking view is now faster and more useful, it is the same one used in mate 8. I still strongly prefer vanilla android app switcher it gives a better overview, I think the overview is a big problem in Huawei's app switcher solution. If you are going to switch with one of the 1-2 recent apps it is not so much of a big problem but for 6-10th-20th you need to scrool a lot.

Now when I use Huawei Launcher I am so far very satisfied with the speed, but again.. lets see how fast this device is in a few months usually after a new re install the device is usually fast...

I hope it is not the case with this.

I am still not able to find the Marshmallow battery stats how the hell do I access that ?

I only see this battery management which is Huawei's own solution.

Cat6 still exist but it has been renamed now to "carrier aggregation" so it still should use CAT 6.

Some users did report here that you was not able to hide the navigation button at the bottom I can confirm I can I hide mine just like with lollipop thankfully!

The build seem stable so far it has crashed 3 times, the two first times was when trying to do a antutu benchmark store, it crash every time and never finish.

3rd time was when I was going to switch default launcher from nova to huawei, then it restarted.

Do I regret upgrading to Marshmallow ?

I see this update as a life saver, just like with lollipop update again it feels like we have got a new CPU/GPU in the device.

so it is a very important update.

I cannot coment on battery life yet but all I can say it is not worse then before, but it is probably a lot better.

Ram mangement seem to be better perhaps little bit more aggressive now..if apps are loaded in memory they usually open fast if not there is a few second delay so I would recommend to not manually clean some of the apps (snapchat I recommend to manually clean if you do not use it all the time cause it seem to drag down system performance if it runs in the background)