hi! i'm new to e-cig, but i did get a provari with big daddy tank and it's been amazing. i haven't smoked for three weeks (although i cheated a couple of times when i was out with friends) and i hardly miss it. anyway, what's the difference between dual and single coil cartos? i know dual has two coils and single has one. but how about taste and vapor production? and what's the best carto manufacturer? i have got a several boge xl cartos but they are running out and i want to see if i can get other ones. thanks!