After one month of using 510s and 801s, I find the weak link to be the feed system--not the batteries. So here's my idea: get rig of the whole cartridge approach. What's needed is a drop-in tobacco "tank" similiar to an ink cartridge. The e-cig obviously must be designed around it. I think that would be great if at the start of the day or week you drop in an e-tank (yeah!) that doesn't leak.
Designers get busy.
Designers get busy.