It basically does a lot of what the autocannon can do (minus closing holes / destroying factories) and doesn't require losing your backpack slot. I love it
2 shot hulks to the face, most automatons with vents like tanks and turrets can be killed in 6ish shots, which is I think 1 short of a full mag. Doesn't take a backpack slot, very long range.
I find running it either as a stealth build w/jetpack/shield or with a Rover to clear trash quite fun. Harder to make work with bugs so bring lots of orbitals and strikes for chargers and bile titans.
If you hate devastators and hulks, have decent aiming, and you are good at positioning and staying away from immediate danger it is amazing against bots
Vs bots it's amazing. 1 shots walkers if you hit their top leg joint. 1 shots devastators with a headshot and 2 shots with torso hits. 2 shots hulks with headshots. You have to hit turrets and tanks on the vent a few times to take them out, but I usually run a 110 rocket pod which almost always takes them out in 1 call-in.
The only problem with the AMR is the sights feel off and you gotta Kentucky windage it a bit.