My Lumia 950 XL is also working great. No crash, or reboots, or anything really.
The creaking cover sound is there, but I know why it does that. Nothing that I have no seen before from removable covers.
Beside that, and the small bug of Windows 10 Mobile (nothing show stopper, just a bit annoying), and how battery life isn't great Taking pictures and Edge really eats things), and the fact that the brightness control is annoying and can't cycle to 0%, and things like that, nothing that Microsoft can't fix over time. All in all, it is a great solid phone.
This is my first Windows Phone, and it honestly surpassed my expectations. As for people who get angry at Microsoft for porting features to other phones, honestly, they are not as well implemented as on Windows 10 Mobile. For example Grove Music is HORRIBLE on Android, but a joy to use on Windows 10 Mobile. Cortana fully works on the device, you can integrated with Windows 10 PC (I expect further integration in the future), and things like that.