I vape 15/85 juice in my tanks and don't have issues with RTA's. Of course, every type has it's own little quirks on how to do it. I also don't do low sub-ohms either.
Fogger, Aqua, Orchid, Elrkonigan...all slightly different wicking and builds.
The Fogger v4 and Orchid v4 have bigass channels and airflow. Especially the Orchid v4 and v6.
I've heard the Silverplay RTA is another contender for RBA performance in a RTA, but haven't tried one.
This is my Orchid v4:
Peeps are modding them to make the airflow and capacity even larger. Me, I just used the KF full tank instead of the stock Orchid one for extra capacity...no drilling just yet...lol
Since so many clones are made by so many companies, there is a LOT of QC variance too, even from the same lot. I have two Aquas from the same vendor, and while one is perfect the other has never worked quite right. It's just not machined well enough.
CNC tools & dies gets worn out over production runs, if they don't keep up the maintenance, bad QC will happen.