I own one rda, a Magma Clone (no idea who made it, I got it for free...) No complaints here! I have had it for about 6 months now and have put all sorts of builds in it. Hell, I managed to squeeze dual parallel 26 gauge in there.... I have also taken it down to .13ohms, which is a lot of power! No issues with the insulator at all. As of a week ago, the post screws have been starting to strip. So overall, the Magma gets a huge thumbs up from me. It makes me a bit sad that I will have to replace it soon... I might end up buying another one. lol. I hope this helps!