The 28mm would pair nicely with my 28mm Sherman RTA.

26650 might be adding too much to my already large selection of batteries though.
A lot of 22mm atties don't appeal to me, I haven't seen one that's really jumped out at me as 'I have to have that', except maybe some of the MTL RTAs in 22mm. Most of the RDAs are 3-post designs and such that I don't like.
I haven't heard of the Dominus, I'll have to take a peek at that. I'm not sure what my next tube mech is going to be, I'm still debating whether I should get another tube or a parallel box. I love tubes, but I don't have a parallel box yet...