Maybe I'm just a weirdo but I don't do single coils ever. I like a hot vape with clouds and flavor both. I use low builds. .1 ohms to me is perfect. .25-.3 in series. Lowest I've gone so far was a .07 and that was a bit much. Won't do that again. 24mm Goons were all I used for a while. Love 'em. The Vandy Vape Icon (not Iconic) is my go to for series. Then came the Dead Rabbit and Drop. I want to get a lipo and a 30mm rda but I keep hearing that the 30mm's are not the best for flavor.
A single coil can be both big and powerful enough to give precisely the type of vape that you say you like. Here's an example of a single coil in my gold Goon 1.5 that I use on my Surric X-Vault PWM mod:
This one is .18 ohms in the 30mm Deathtrap. I use it on my Vapergate The 99 stacked tube mech with dual iJoy 26650s:
30mm RDAs can give really excellent flavor, but unfortunately most people simply don't understand key important factors like the size of the coil build, the wattage, draw strength, and positioning of the coil(s) in relation to the airflow and airflow settings. If the distance between the air hole and the coil is too long, then most of the airflow misses the coil as the focus and speed of the airflow is weakened too much by the time it reaches the coil. Similarly, if the coil is not positioned immediately in front of the primary airflow's center location, you won't get an evenly distributed cooling; remember the cooling effect also is amplified by the evaporation itself, which, in turn, is amplified by both speed and stability of airflow. Air moving too slow across one particular area or part of the coil's surface creates an imbalance that IME will cause flavor to be degraded as well as accelerates gunking of the coil. Moving too fast it just dilutes everything and results in the kind of turbulence that messes up the stability, or smoothness required to be able to get that warm/hot dense saturated flavorful vape. Airflow stability issues can also occur if the distance between the air hole and the coil is too short, causing air to tend to bounce off instead of evenly distribute itself around the center of the coil upon impact. The strength of the draw and the amount of restrictiveness really need to work in tandem to produce not only the right amount of air for the amount of vapor production you'll get, but also the speed at which the air hits the surface of the coil is paramount. With a bigger RDA there's simply a bigger volume of air inside that can easier start to dilute the flavor unless you know how to make sure the right amount of air gets pushed in the right directions using the right amount of pressure. Air pressure is also the key, as the only way to get a jet stream of air to reach far enough to meet the coil's center area location in that 30mm Deathtrap shown above is by making proper use of pressure, and, you can't get much pressure if you don't allow at least
SOME amount of restrictiveness to be in there. That IMO is where most people fail when they claim poor flavor.