I've got a set of 4 PFs I,ve been using exclusively since March 2013. Love 'em. The first battery that will vape, for me, for a full 24 hrs between charges. I now have a total of 10 (6 I have not yet used). I don't sub-ohm. I actually prefer about 2.5 ohm coils on a PT or my new love Kayfuns. NOTE: these are 10 Amp continuous batteries NOT 20/30 Amp so don't mis-use them.