Lumia 640. Mostly happy with the upgrade.
- Upgrade process was very easy although it took quite a while as after the actual upgrade, it went and re-installed all my apps.
- Styling is excellent - it looks far more polished, it really looks so much better than 8 did.
- The core applications are generally much better than 8 - Mail (now Outlook Mail), Calendar (now Outlook Calendar), Maps, File Explorer, Edge (replacing IE) - All major improvements over their predecessors.
- Most small apps load quicker than they did before although I have noticed that when you click back, not all applications close anymore - more like Android / IOS where they keep running instead of being closed.
- However large apps (games) take a little bit longer to load and one of the games is noticeably slower
- Also started getting a strange error now where I play the same XBOX live game on my PC and phone and it now tells me I'm logged in on multiple devices even after closing the game on my phone.
- Battery life seems to have taken a bit of a knock, but it could just be me playing around with the new phone more often - will keep an eye on it.