My only PV is a Joye 510. I like the 510 a lot but the USB PT I bought for it only lasted me 6 weeks before it stopped working. I was careful with it because I read that the 510 PTs were pretty fragile but it barely got me a month and a half. Instead of dropping $15 every couple months on a new PT I'd rather buy something that will last me a while. What other model e cigs have more durable USB PTs, or do most of the other models have the same problems as the 510 PTs?