Not sure what planet some of these people are on, but RDA's are much easier to build and rebuild and rebuild and test and retest on. You don't have to worry about wicking or spacing coils or any of that B.S. Just wrap a coil, test the ohms, and light it up. If it works good, pull a wick through it and vape the crap out of it.
RBA's, especially geni style are a bit of a pain if you don't know what you are doing.
Test out what coils work well on a RDA and then worry about mesh and ceramic and whatever later.