Only had one of the many knock-off devices fail. And for the price I paid for it it was replaced and was still under name-brand cost.
I have had just as many Joye batteries fail, in what I consider an early amount of time, as no-namers, have had roughly the same experience with knock-off clearo's and such. Some body stated they would buy the name-brand to support innovation, but Joye hasn't really been lighting up the world with anything new and exciting. Smok has put out some good devices, but if you look at Kamry, Siegeli and others, they have really been pushing new (even if they are clones) devices out the door.
Cartos, when I use them, are almost always a brand-name buy, unless the deal is way too good to pass up (I buy lots of stuff to give away or re-sell at cost). I preferred ST and Boge to any of the others due to durability and the fact that they weren't too pricey to begin with.
I bought a ton of "stardusts" from Vapage a while back for a buck a piece, and they were perfect for starter kits I would put together for people wanting to try out. And iVape had some starter kits that were so cheap that I could afford to give them away.
So does name brand really matter too much to me? No, I would have to say not, at least most of the time. Even though I can't say so, I think a lot of the products out there are probably like car batteries; there are only a few plants that make them, yet the are re-branded depending on the place selling them.
Just my input!
Salky