Mike: I like the Trangia stoves, too, though I've never really played with the simmer ring. (I tend to use boil-water-and-dump-in meals.) The movable part of the top on mine seems awfully stiff - seems like it might be difficult to adjust with a stick. Is that a concern, or does it just loosen up with use?
Also, I use the Clikstand stove base. I don't see any way that you can use the simmer ring with it, given the interference by the walls. Am I missing anything, or is it just the price you pay for the overall efficiency of the Clikstand?
Finally, just out of curiosity - which stove base do you use?