First check if you can move to 5.0 or 5.1, before moving to 6.x
My phone can't upgrade OS's and I might get a new phone with Marshmallow as the OS so that's why I was asking, it's not so much upgrading to a new OS version, it's a matter on if it's better and more stable. I've use Android as my go to smart phone so I know that Google does improve but I just wanted to see how other people liked it.
With the exception of 1 or 2 occasions, every new Android version has usually been nearly universally better than the last one;
- Lolipop added a new runtime which significantly improves app startup time and app performance, tweaks to the interface to make it more intuitive and easier to use (without making it completely different), improved lock screen, battery life improvements, notification improvements, better call quality etc.
- Marchmallow then adds improved searching functionality, even more battery life improvements, new sharing features, better permissions control, backup and restore functionality for apps, improved SD-card support and an experimental Multi-window feature.