Agree on the Supbox being fat for 22mm attys, they look out of space on the Paramour too, kind of funny on the MIXX. On the Converter most of them look weird too (IMHO)
Yep, the Balance isn't perfect 510 wise, some attys screw all the way down, others leave you with a little gap, with some silicon (or delrin/ PEI) spacers that can be sorted out. In the cave they still sell those transparent and black silicon ones, they are quasi invisible and fill out perfectly any gaps.

Look-wise (if we want to be picky...) the ones which go well: Insider, Flexy, Balance, Kizoku, Sunbox Easy, maybe (probably) the Katana, Digiflavor (never had a closer look on these two). Someone mentioned that the Kizoku feels cheap, on photos it looks aright, at least, hehe, never seen one in life.

Just about the ones, more or less available on Chinese sites.

Ps.: I'd love if they cloned the Zero Nega 2 ;)