Windows 10 for phone...
It is not much convenient for me...touching the screen is not as wp8.1(it need more improvements)
Photo app crashes every time,glance screen,data toggle,flight mode,as more options doesn't work very well for my phone,also the screen shot is not working(they didn't implemented it)
In phablets (as I'm using L1320) components(text,buttons,etc) are not arranged properly.They are always overlapped.After switching off the phone the goodbye text is always displayed on left side(slightly upside)not in middle...
Also the I can see one or two white lines after pulling down the notification bar...
Battery saver app not showing any battery usage of the apps
Battery drains faster than wp8.1
Also the os is little bit laggy (it is like i'm using android phone XD
Still it is in TP so these are normal bugs
But the pros are nice...
App switching is faster than w8.1...no resuming screen(that's why it eats battery I think so)
Notification panel is much more better now
Settings are arranged properly
Keyboard is awesome(I got every thing in the keyboard l like the new functionalities of keyboard)
Minimalistic design is implemented in the UI(I.e. Gerry color in buttons)...it looks better than only black and white UI design
Also the calendar and mail(aka outlook mail) app are much better now...minimalistic design...