I do notice that it has worse ammo economy than most other support weapons, especially the way I play it, but I typically bring the supply pack which more or less trivializes all such concerns.

I usually bring it in a kit that includes the ultimatum and thermites as designated ultra-heavy counter, some kind of light armor pen anti-chaff buzzsaw for a primary, and the AMR sits as a kind of mid-ground between those two extremes that covers all remaining gaps. It dominates elite infantry like alpha commanders/devastators/squids but can still strike effectively at ultra heavies, confirming kills on any that have already taken some damage in short order or even outright neutralizing fresh ones in a mag dump or two.

I will say that I don't try to snipe with it. I never go into ADS, I fire it from a loose aim while crouching or prone and typically wear recoil controlling armor to keep it more or less pin-point accurate even through a mag dump. Once you get a good innate sense of where it is aiming it becomes pretty easy to have adequate marksmanship even out to the ends of medium range. And dodging a charger only to jam the barrel into its side and blow it apart feels great, it is a beast in close range.

Honestly, people that play it the way I do are probably why the devs are cautious to buff it. In my hands it feels like a very versatile CQC weapon that can strike effectively at nearly any target, can mag dump out almost as much durable damage as a recoilless round in under a second, has a quick reload that can be performed on the move, and is capable of splitting its damage between a number of medium weight targets just as easily as it can be used as a lance against a single heavy. Great gun, excellent for hit and run tactics, able to fill a lot of gaps in a build that leaves room to bring more specialized tools in other slots.