Second stages are your preferenceThe 82x comes with an Ultra, the 28xr with a dual.

FWIW, the Ultra Adj and HR (aka Dual) Adj are the same reg - they literally have the same reg body part # - except for the gimmicky tilting purge button and Twin Power System on the Ultra. The latter slightly moves the orifice to reduce or increase cracking effort. They originally developed it as a marketing response for their otherwise non-adjustable regs, but I don't see any reason for it on an adjustable reg like this and it introduces a flimsy plastic piece into an important part of the mechanism.
I think it's telling that Mares does not include either the tilting purge button or TPS it any of the versions of their second stages that they sell in their XR tech line.
IMO, their current flagship second stage isn't either of these. It's one of the metal bodied adjustable seconds, either the Atlas Adj or Epic Adj. The only difference between these is the Epic has TPS.