It's a coin flip. I've bought clones (knowingly) that performed as well as their parent and also bought a few that "tanked" on day one.
One was a Protank clone (version 1) that would have leaked through a whole roll of duct tape.
In another thread, someone asked about using clones to cannibalize parts for the original. That too would be a coin flip. Cleito has been out for a while, so finding one in someone's clearance section shouldn't be hard.
Give VapeCrawler a try. It's like Google for vaping gear. It doesn't hit every site, but it covers a lot of'em.