I like both, but a good Saw LMG is a clear winner in most situations. ARs are a bit better in situations where you need to hit crits/weak spots at a greater differance, but even then a LMG Saw can be better if you have the right mods and just focus on your shots.
I honestly feel that, at least in PvE, that LMG and detonators might be on the overpowered side.

