Well I have seen several comments saying if you own the original there is no compelling reason to upgrade outside of the easier fill and afc control. Lemo 2 gives less capacity, and more air flow. Two downsides for me. I like the higher capacity and tighter draw. I have my originals set to almost 3/4 closed. Seems like these new tanks are catering to much higher wattage vaping. Again not my thing. I think I will save my money and stick to my originals. Maybe I can find some fire sales on the version 1 and grab a few more.
If they make a higher capacity (5ml) version then this will replace the original hands down. You can manage the higher wattage with higher ohm coil builds and the air flow can be shut down completely. Just so much more convenience not having to remove the tank, unscrewing the bottom and then removing the screw to fill like on the original Lemo. The tank remains installed during the fill process.