In summary;
buy a higher nicotine content juice. (5 bucks for a bottle of some good 24mg stuff?)
Buy a low resistance cartomizer/atomizer. (8 bucks for a five pack of Boges?)
4.8V is more than enough to get to the "extreme" of vaping. (keep yer damn twist, it works!)
Throwing money at large, expensive, shiny phallic shaped PV's should not be your first course of troubleshooting when you have a perfectly good, transportable battery already.
Nicely done!

I agree.
@OP: Just don't use dual coils on your Twists.