I haven't tried any of the above RTA's, except the Kayfun, but I think you'll find that the last couple months, and perhaps more specifically, the last few weeks, have seen the release of many highly affordable RTA's that allow for both great flavor and airflow. I have the Lemo and Billow, two atomizers under 40 dollars, and both are great for lung-hitting and the flavor is really quite special. If I had to recommend one between the two, it would be the Lemo because the Billow is kind of a temperamental little ...... That might just be me though, cuz I've heard of plenty people who've had a great vape with little leaking on the Billow. Also, it seems like a lot of these new, affordable RTA's are best suited for dual coils (except the Lemo). Some other RTA's which have literally just been released are the Project Sub-Ohm SiverPlay and the UD Goblin. I ordered the SilverPlay two days ago, and it looks pretty sweet, with lots of airflow options, including a couple through the negative posts, Plume Veil-style. Anyways, I guess my point is this: you neither have to spend over fifty bucks nor purchase a clone for a crazy good RTA experience anymore.
Also, though not an RTA, I've had a really good time with my Aspire Atlantis. Clouds for days and pretty decent flavor as well. Of course, you'd have to replace the coils, which can end up being quite expensive.