Even if you've honed your eye for fake online reviews, you can still end up purchasing a gadget that turns out to be a dud. Reader A3sthetix suggests searching out common repair issues before buying.
People often ask me if they should purchase some gadget I haven't used. I'll look up the usual reviews, but I also find searching troubleshooting website FixYa and other forums for product problems before purchasing helps a lot for knowing what to expect. FixYa has been very helpful in determining which products are riddled with issues and bad support.
You'll still need to keep in mind that every gadget has occasional troubleshooting issues, but if a particular gadget seems to have a common and recurring problem, it's a good indicator that you may have the same problems.