I mostly used a derringer rda and found the only coil head that wasn't complete crap for the big baby is the rba head. The disposable heads were all terrible. I'm assuming the ridiculously good vape I get from the rda ruined me for disposable heads. The rba is $10, comes with Clapton coils pre installed and it can easily be dry burned and rewicked many, many times. And having a spare on hand and already wicked makes swapping them out on the fly super quick and easy. Just a few thoughts. Good luck.