I want to put a medium-small light on my home defense carbine (11.5" DDM4V7 upper) and I want to put it in a Proctor PLM V3 which works well with Streamlight Protacs.

But do I want the 1L or the 1L-1AA?

The 1L-1AA can use a AA in a pinch, which I could see being invaluable, but when using the AA the lumens are cut in half & the AA battery fits loosely in the body. And the plain 1L takes only CR123 batteries but it seems more simple (rugged, foolproof) and it's a bit more compact.

Right now I'm leaning towards the Protac 1L

Pics of intended host rifle (on left):

Poll added.

Frank designed the ring mounts before the Streamlight Rail Mount lights came out. The head of the handheld is not exactly designed to run on an AR. That being said I have one on my RECCE gun since I recently bought a 1A-1AA rail mount to go my SBR. It's a slick setup that is light and minimalist. Frank has since come out with the direct mount for the rail mount series which will get the light super tight to your rail.

If you're not going to run a tape switch, go with the ring mount, if you want that option, run a rail mount. Either way 1A-1AA version.

Frank has one that's lived many thousands of rounds in the muzzle blast of his BCM. Maybe not made for it, but it impressed me.