So far I have used (ltv9) cartomizers from smoke51, loong totem, e-cig and vapor king. There is one univeral truth with these things. If you let them get too hot the wick chars and they taste horrible. I have found only one solution to this problem. Constant cart switching. If I rotate 4 carts rotating about every 5-7 puffs I can chainsmoke without charring. This is the only thing that seems to work and allow me to get all 200 moderate puffs without toasting the cart first. If anyone else has experienced this and come up with alternate solutions or mods let me know. It's all I have come up with to date.