In order of favorites:
Provari/IBtanked carto tank. Mostly used with Boba's Bounty.
iTaste MVP/IBTanked carto tank (I borrow a V2 when at work and set it at 8 watts). Mostly used with Vapor Chef's Honey Pearry.
iTaste SVD/IBTanked carto tank. Used with NicQuid's Day Break.
I've tried microcoils with cotton and while it truly is delicious, ALL of my juice, even my apocalypse stash, is all 2.4 mg nic. That would destroy me in a RDA. To replace them all with 6 or even 12 mg would be waaaay to costly. And also, I cannot justify the $ for the amount of juice RDA's go through. Otherwise, yes, they are great.
I dripped using an old 510 joyetech atomizer for around five months back in the day before I discovered carto tanks. The thing I hated the most about dripping was the hit of death. I could sense it coming, and would drip accordingly. But constantly dripping, though delicious, was not what I was wanting out of vaping. So that's why I stick with carto tanks.
RSSTs and RBAs such as the Kayfun, Russian, etc., I have absolutely ZERO desire to use.