Here is my take on this as i went thru this process last winter.
1 - First of all you want the hammer drill. Not for the hammer function, but because the internal components are built for more abuse.
2 - If you plan to use anything up to a 6in auger the Rigid Hammer Drill will be just fine.
3 - If you want to use an 8in auger the Milwaukee Fuel Hammer Drill is the better choice. This drill has burned up using an 8in auger, albeit thru 24in of ice.
4 - Price: The Milwaukee will cost more
5 - Warranty: Rigids lifetime warranty on the drill and batteries (if you register on their site, takes 10 mins) cant be beat.
For my purposes (I live in MA too) I went with the Rigid as i only use a 6in auger. Last season i punched over 500 holes thru 18" of ice, not a single issue. My average holes per trip is about 60-80, with battery to spare.
I had the Clam drill plate but found it unnecessary for this setup and just added weight. I simply use the drill with the side handle with an adapter and a small disk with a cord in case the chuck loosens up. This also allows me to remove the auger from the drill on the ice to screw in pop up anchors. Or for general use around the house. Its also nice that it pops apart so easily for storage and transport. Total weight about 10lbs
As we are both in Mass, hit me up this season and we can meet up so you can try it out.