I started off with a greensmoke 2 piece e-cig and was very happy with it at first. Great vapor and carts lasted very long. After the second month of quitting real cigs and just vaping my greensmoke batteries just didn't want to keep a charge or produce much vapor wether with a new cart or ones I refilled. I still love the greensmoke passthru but have switched my main pv to a totally wicked tornado! Major upgrade! I am still learning the ropes and have spent countless hours on this forum learning from all the people who post about everything. Thanks to everyone who has posted to this forum ! I have saved $765.00 and not smoked 2550 cigarettes in 85 days!!