This firmware has many many bugs.
1. fever, low power consumption compared to Android 4.4 version is slightly larger (already optimized, such that heat, power consumption is a serious replies please inform specific usage scenarios);
2. You can not use Google Installer (already referred back to the app developer adaptation in);
3. Visitors model some small problems, temporarily is not recommended;
4. Application to encrypt the message after being given; (Beta repair)
5. Set - account, even now the interface can not slide up and down; (Beta repair)
6. Set - power management, power has been displayed 100%; (Beta repair)
7. part of the interface box style bomb error; (Beta repair)
8. document root directory display 0KB file;
I got a second beta version for MX4 Pro.
I uploaded to MEGA.