Nougat battery life (Latest BTU) vs Marshmallow battery life (March firmware)

So I figured that after seeing Gsmarena's report about battery life being worse on Nougat that I'd do my own small test between the two. I've always said that the March firmware had the best battery life of any firmware on the Exynos S7 but it's been a while since I used it so I figured I'd see if that was still true or not.

As always, it's best to compare your own battery life between different firmware rather than simply looking at someone else's screenshot. Playing games will drain more battery than watching a video streamed from Netflix or YouTube. Using the web browser also taxes the CPU more than general video streaming so that too can muddle things a bit.

Anyways. On both firmware Bluetooth is enabled (connected to my Fitbit), this is solely a 4g always on test. Knowing I can hit 7 hours SOT on Wi-Fi means didly squat when I'm out of the house. Auto brightness is enabled. Spotify was used via SD Card streaming for over 2 hours on both firmware. Usage habits from both days were roughly the same apart from
A:
On nougat firmware I was on the phone for 1 hour 30 minutes, vs 1 hour on Marshmallow.

B:
On marshmallow I went on a 8 mile walk and had the GPS constantly activated in both S Health and the Fitbit app for just over 2 hours.

C:
Location is set to battery saving on Nougat. In marshmallow it is set to full (GPS, Wi-Fi and mobile networks).

Nougat 1 Nougat 2

Marsh 1 Marsh 2

The nougat firmware had been used for almost two weeks so had plenty of time to settle in. The Marshmallow firmware is only 2 days old and so still has some time to optimise itself. No battery saving apps of any kind were used. I installed both firmware clean via ODIN.

The result for me is an easy win to Marshmallow. I always say that if your battery life is good on newer firmware, it would be amazing on March marshmallow firmware. I wish I could get the same 4g battery life on Nougat but I simply can't. I don't want to have to disable or lower location accuracy, or be forced to root etc. It should be as simple as install firmware, enable features you use and that's the end of it.

Tl;Dr - Marshmallow standby time is roughly 20% better (24 hours) vs Nougat (20 hours). Screen on time is roughly 35% better on Marshmallow (5 hours 50 mins) vs Nougat (4 hours 18 mins) despite running the GPS for 2 hours on Marshmallow which is a pretty big battery drain in itself. Test was done using 4g only, no Wi-Fi use whatsoever.