1 no not the same electronics. But the cartridges are threaded the same and they are interchangable.
2 LTV9 has the lowest voltage output I have seen from any of these. The e9 is better but still not as good as the smoke51 duo. That thing is a beast and has the highest (unmodded) voltage output I have seen on a 2 piece that fits these style carts. The vapor production is nothing short of beastly.
3 greencig is a whole other device. It is not compatible. They are both cartomizer based but they are threaded differently.
Hope that's helpful..
Thank you all for your answers to my questions! Each of you has offered an additional something extra.
I've quoted Mac here because of his distinctions within the E/V9 family and the details about the smoke51. It caused me to pull up Leaford's Smoke51 video review.
Since I like very good vapor, but also want good flavor and throat hit (and easy draw and longer cutoffs), I'll stick with the GreenCig carts (on KR808D-1 batteries) ... along with my penstyle, Prodigy, and 510, that is. [And I'm giving serious consideration to getting the M702 aka Revolver Elite. I think a super-mini might be a fun change of pace ... and that PCC is neat.]