I had decided to get the Ultimac rail to mount a small red dot but I see that Sampson now makes one called the Hannibal. Does anyone have experience with both? Installation, sturdiness, holding zero, mounting an RMR….? Which do you prefer?

I don't have experience with the Sampson, but the Ultimak is good to go. I've had one on my Mini-14 for over a decade now, and also have Ultimak rails on my AK-103K and M1A Scout.

The Sampson looks like the same general form factor as the Ultimak, but with the rear 1/3rd milled flat and drilled for directly mounting micro red dots like the RMR.

So if you're planning to use an RMR or similar handgun optic, the Sampson would seem to be the natural choice.

No experience with Samson, but I've done two Mini's with Ultimaks and they are GTG