Few hours of testing/fooling around:
- sensors not working
- GPS not working
- Bluetooth file receive from another Sailfish phone (Moto G4 plus) works. (No other Bluetooth testing done.)
- Samba app not working. (Works on Moto G4 plus.)
- Occasionally WiFi stops working. Reboot fixes it.
- Not possible to setup "General email" account. (Works on Moto G4 plus.)
- Camera works, but not possible to select full resolution 24MPix mode.
- Video recording resolution is 3840x2160 4K? (By looking captured video file details.)
- Haven't tested SIM/phone functionality yet.

The XperiaX is in 2.1.3.7 after it performed OTA update. My Moto G4 plus uses sailfish version 2.1.0.10.