Android 7.1 VS Android 8.1 (which is best?)

Android 7.1.1

Useful:

1) Stock without customized OS

2)Apps works faster in terms of opening time of an app , speed

3)Better Security (No such flaws found )

Issues:

1) Low Memory By default

2)Games with 150 MB or more RAM usage can't be played well

3)Few Apps are able to support dark mode by toggle switch method

Android 8.1

Useful :

1) All of the Google Apps are now supported and can be updated from play store

2) Games with 150MB or more of RAM usage can be played and chances of crash are less when compared to Android 7.1.1

3) Most Important Update is , Google Camera Go ,newly launched go edition based camera app now supported for Nokia 2 where you can try the Portrait Mode

4) Dark Mode support are available mostly for all apps with toggle switch method in apps

Issues:

1) Experience with this OS for first few days will be good to go but as days goes on and cache starts filling up ,device will become lag

2) Few Recovery Functions are still not in working condition(if any one forgets password then it's difficult to get back to normal state)

3) No Vo-Wifi features are made available on both OS

4)Default Camera App has issue while taking videos in low light by default

5) Security Flaws are still present in this build

Both Have their own best of best but in terms of working and security point ,Android 7.1.1 will be best one to choose even after it's lifetime

The Oreo update isn't worth your time. While there are some pros to it, it slowed down the phone drastically. If yours is still on Nougat, just stick to it because the performance is way smoother.