Basically, the E8 a M8 in a plastic housing and a better camera.
The E8 runs at least as fast as the M8. The E8 has already Android 5.0.2, while the M8 STILL has 5.0.1. Thus, the E8 is currently still the better software.
The plastic case even has advantages:
* 15 g lighter (absolutely felt, blind tested)
* Is less warm than the aluminum from the M8
* Better reception because metal shields
In addition, the plastic feels anything but cheap to, but is wonderfully crisp and even looks chic in black with gold / brass-colored surrounds the camera.
The camera in the same condition really something clearer photos.
Here the decisive advantage for me of E8:
1. Much cheaper
2. weretiger plastic, 15 g lighter. Design I do not care, because anyway a shell drum
3. Newer Android version
4. Better Camera
5. Better Reception
Everything else is the same M8 yes. The E8 is running very fast, no shocks, super display and of course also a great sound from the front speakers.
My conclusion: Even if the M8 and the E8 would cost the same, I would buy the E8.