About a month ago I bought a DSE901, my first eCig, from RuyanDirect; it arrived from China (took more like a week than the advertised 10-12 days, and I'm in the middle of nowhere). The atomizer and the batteries both say SLB on the flush gold end surfaces. They also say BD, and a small 5-digit number (serial or batch number?). My battery and atomizer have different numbers on them. Like, the atomizer reads "SLB BD 78524" running around the circle of the flat part of the gold battery contact.
I like the flavor and vapor. I got some spare atomizers for it from the same place. I am just as happy with those. I got a 501 from another company, and then some spare attys from Ruyan, and I just don't like the 501; mine is an auto, perhaps that is why. It feels like I'm breathing air. It's hard for me to get much vapor or hit from it, and no taste. And one of the batteries on it already blew out, just went dead, and I had not been using it much because I preferred the 901. So I'm a bit concerned that if I got an RN 4075, it would behave like the 501 since it runs hotter and is supposed to give better TH (sounds like the way people describe the 501). I really like to be able to taste the flavors. And the 510, despite not giving out much flavor or vapor for me, seems to suck up juice about twice as fast as my 901. Could anyone compare the RN4075 to the 510? I don't think I would want to stray from the 901 without a little more confidence in what I was getting.