I'll do a report on my Mephisto rda clone because I'm very impressed by this dripper..
It's a 22mm, 3 post design. The posts are very big with HUGE (3mm) post holes, so it'll fit about anything. The screws are large flat head screws. Building it is super easy; I don't need such huge post holes since I mainly do single 28ga coils, but it's nice how super easy it is to thread the leads in, and the screws grab onto the leads very well.
The drip well is also huge, 4mm deep and holds a ml of juice. The airflow is easy to adjust from fairly tight to very loose, with either one or two holes for single or duals. The drip tip hole is has a delrin insulator to keep the tip cool and I've read it produces better flavor. It holds tips in very snug with no wobble, even using my vase shaped ceramic tips I love which often wobble on devices. The 510 connection is adjustable which is rare and nice to have.
So everything is pretty great as far build and function, but the most important thing of course is flavor. I wasn't expecting great flavor because the chamber is large, but both St. James and Pirate's from RBFS are slammin' in it! I think the large posts help flavor because of the space they take up, the domed top, and I don't know why the delrin up top would produce better flavor as I've read but it just may be true. My personal favorite device for flavor is my Atomic rda, and surprisingly this large Mephisto seems close to or on par with that.
Very happy with this and highly recommend, for only $15 at 101Vape. Can be used for cloud or flavor chasing.