It looks like a school bus. I don’t see how more “special” this would be for field use vs a traditional RD.
It has several advantages compared to something like an RMR. In an RMR, the emitter is at the back and it projects forward onto the glass. The glass on an RMR is kind of like a cup, and it can catch debris and mud if you are crawling around. If you get mud on the back glass of the RMR, then you can’t see the dot and it is hard to clear. Same if you get dirt on the RMR emitter.
In the Acro, the emitter is contained within the body, so you can’t get any debris (water, dirt, etc) between the emitter and the glass. Since the front and rear glass of the Acro are flush, they are less likely to scoop up or hold debris and they are easier to clear of water, etc.
Also, unlike the RMR, you can change the battery of the Acro without removing it. Aimpoint is also claiming it is more robust, though time will tell.
Compared to other Aimpoint red dots, the Acro is apparently significantly smaller.
Finally, the guys at Inrange claim it is easier to pick up the dot on the Acro than it is with the RMR.
Downside is that the Acro seems bulkier.