in airsoft, AK's make decent DMRs
in reality, M14 is the way to go
from a technical standpoint of the internal workings, the M14 IS better. The mechboxes are on par with eachother, both very good performance wise. But the M14 has a superior hop chamber.
As far as working on your mechbox, how often are you REALLY going to be working on it? Because if you're planning to have it break down every week, you might as well buy an ICS lol