The difference between a traditional listing and a flat fee MLS listing broker is not great other than in price and seller participation with scheduling requested showings. A flat fee broker adheres to all of the same licensing and knowledge requirements as a traditional broker. In other words, they have the same background.
The main difference is that flat fee brokers recognize that technology allows for them to handle a higher volume of listings without compromising quality. Each flat fee company has a different business model so I cannot speak for all brokerages, however, most local flat fee brokers allow their sellers to participate in the MLS with the opportunity of full representation. Each additional such as negotiations may carry an additional flat fee.
This business model allows sellers to most often save thousands of dollars in commissions. If you would like to preserve your equity and keep your money in your pocket, a flat fee company is worth a look rather than trying to "go it alone by listing fsbo."