Agreed. I've been contemplating the Siren for a while, but I found my SJMY Doggy in the meantime, and it's become my go-to, at least for the time being. That spinning AFC ring is an annoyance I can live with. What I would like to have is an rta with an adjustable internal airflow intake opening, so that every vaper can dial in the exact size they want--from tight MTL to wide open DTL. I'm sure it can be done.
I've not tried that doggy but I was under the impression it was more MTL than RL...
Your right, adjustable inner airflow as well as adjustable outer should do the trick..
although, it would never be able to do everyone because the wicking ports (or wells) need to be larger for the DL people - more power = more juice so they need larger wicking ports.
As it is I'm not sure whether I'd need to enlarge those channels on the Siren if I ended up modifying the Siren to suit me. I don't think I'd have to but you never know.
But yeah, at the very least with adjustable inner airflow they could do two perfect rta's that really would cover everyone..