I have had mine since they came out, using multiple RTA and RDA atyy's. IMO, RTA's are VERY hit and miss, they just were not designed with Ni200 coils in mind. They can work, and work very well, but they can be equally frustrating.
RDA's are easier to work with and easier to make corrections on when something get off. My personal favorite RDA is the Holmes V2. With Ni coils, you are going to have bigger coils, there is just no way around it. With my Holmes, I can build a 14wrap 26g coil that fits beautifully in the 2 post design. A 2 post designed RDA is the key to sanity, it keeps everything simple and minimizes one of the biggest reasons good coils go bad, the leg length.