I'm waiting for my Lumia 950 XL, but I'm worried because I'm reading only bad things about the phone.
Is the Lumia 950 XL the worse phone from Microsoft? or is it only the software?
I need to read something positive about the phone before cancel the order
Congrats!
To avoid any of the problems make sure you don't go lazy and do the same mistake many have done: to restore from an older backup when setting up the phone for the first time. DON'T!! Set it up as new phone and take your time to download apps. Restoring from another phone's backup is a total mess as it is another hardware profile saved!!
Also before anything, search for OS updates and let it finish, even if it appears stuck at 0%. It is not stuck. IF you get a low storage warning just tap on Continue, don't Cancel, it will work fine. Updates take time to download and install so have patience. During this, keep your phone plugged in and ignore the fact that is getting hotter than usual, it is normal as it is charging and installing and downloading things.
don't use any sdcard until you have updated the phone to the latest build and firmware.
Go and disable background apps you don't need to have running in the background but be careful what you disable, you may broke functionalities for the first party apps if you disable something you should not.
Use Skype app for now, don't login into Skype inside the Messages app as it is still beta and could drain your battery.
Windows Hello while it works, it is also a beta for now.
At data usage setting make sure you do not leave the Allow switch for the phone to use Cellular data when Wifi signal is low.
For facebook use facebook beta app, it's working ok, and it's much better than the public one.
Well, hope I got it covered as much as I've could...enjoy