Lumia 640 without fault?

Superb phone, cheap, beautiful, responsive and robust.
I get out of Android and IOS, first use of Windows Phone much more intuitive.
The dynamic tile system and containing the information is much more modern and efficient as icons.
Contacts, Calendar, Gmail sync have made a wink and perfection, I had nothing to do to change the environment.
I still have to test the device on long usage, but this first impression is really very healthy.
Congratulations Nokia and Microsoft and therefore also for supersonic Amazon and perfect delivery.