User reviews can offer valuable insight into a product's real value after the sale. But many review sites also contain write-ups by fanboys, axe-grinders, and even a few shills. How do you know which reviews to trust?
Reviews aren't everything
Finally, remember that even the best-reviewed product may break, and at that point you'll hope that you bought it from a manufacturer who takes after-the-sale customer service seriously.
I've read every sort of complaint about manufacturers, from the ridiculous to the infuriating.
My advice: when it comes to user-complaint websites, don't put too much stock in any one complaint, but try to look for themes - which manufacturer doesn't provide trained technicians, which one delivers poor warranty services, or the like.
See also: Over 1,200 scam websites taken offline