I have an RRT-0 - it's athletic looking, has a great magnetic ring, and throws very well for a single cell.
In the winter, it carries nicely in the lower front coat/jacket pocket.
However, in summer, the bulging enlarged head design can be felt when placed in the back pocket of jeans; although that very bulge on the magnetic ring makes it easily identifiable in the dark, and it also gives the reflector additional diameter for it's good throw.
Thus I'm also looking for a single cell EDC with straight/parallel sides - or sub 1 inch head if you wanna put it that way.
Quark 123 is similar to the 1C - looks a bit plain, with no magnetic ring for the lazy underhand handshake grip.
The HDS Rotary 200 has a wide uniform fat 1 inch diameter from head to tail so it has the best grip of the lot! However this design also makes it the heaviest.
The short travel digital tail end switch is not as ideal as a long travel analog switch for momentary on [u must hold the button down to get momentary], while the stiff tail end rotary dial forces you to hold it by the four fingers overhand grip, and never the lazy relaxing underhand handshake grip.
The flagship Rotary 200 is also conservative on output.
The Lumintop has excellent lumens, but a bit plain and no magnetic ring.
The Thrunite 1C also has 450 lumens, but it looks a little plain, no magnetic ring, and the quality/wobbly head is said to be suspect?
The Sunwayman V10R looks good, has magnetic ring albeit with no standby, however the V10R lacks punch; it has only 210 lumens too.
I think I may be patient and wait a little for some new models to be released with XM-L; the brightness will be great, and the throw will be diminished - however there's nothing we can do about that for now...