Most of the criticism about Best Fares has to do with their poor customer service and the unavailability of "private" fares they have negotiated.

However, their website has a section called "Snooze you Lose" that lists a wide range of sale fares that you can access without being a member. Many of the fares they list are generally available directly from the airline and do not need to be purchased through best Fares. I have found this section useful from time to time, though its organization leaves something to be desired.