The way I see it is Janty has created their own platform to build on.. so all their mods will incorporate the innovations from the stick. So even if they make an sd it will have smart electronics which would make it different.
And now that would be really nice:
1. LONG battery life. Say 500-600mAh minimum with reasonable form factor.
2. metal. Sorry, but SD > JS on durability (I own neither, but come on, look at them, then think about dropping each..metal wins)
3. Reasonable form factor. They did good with the JS sizing. At least the bulk of it, IMHO, should fit in your hand. Recess the atty into the casing like they did on the JS to recoup some space in length.
4. Sane batteries (like JS, SD, GG, etc)
5. USB PT on an SD type device... = very nice, clean and a first. (like on the JS)
6. actual on/off switch desired if it's at all possible to activate in a pocket.
7. adapters. Don't say it, do it. Short of Janty coming out with a truly unique atomizer with 6 months longevity, I don't need more attys that are incompatible. I will however, buy more 510 attys from you if you make the device I want.
That would be an 'SD' I'd want to own. I'm even open on the voltage..I think a consistent 4-5vDC is just fine.
After that plus the metal JS, would come (in my 'ideal world')...juice delivery. Better delivery, and higher capacity.