Considering your "branded" vapers are generally made in China, the safety is there provided you do your research to make sure your "generic" is the same as something someone slaps a label and 100 bucks onto, or, like in my case, is the genuine article.
Buy some weird looking thing from Itchicruthchi Electronics that has no resemblance to anything on the main market and, obviously, you're on your own BUT if you do your research you can make some decent savings.
Like with any new toy, doing your homework is the most important step in the process.