The MT4 is super easy to use..very light weight but no backlight.
The mt4 is not a budget radio it has just about everything all the heavy hitters have, the best value period.

The m12 is quite a bit heavier but has a ton of options.
Dropdown, angle adjustments, two wheel sizes, etc..etc.

I have had the mt4, m11x and now the 12.

At the of the day it will depend what you will using the radio for.
If you're only using it for one single thing..then see if the MT4 has what you need.