I have done both with selling my investment properties. Really depends on the market. If you have a seller's market, then by all means try flat fee to list on MLS and hold your own open house. Stage to some degree. Advertise your open house everywhere - via MLS, Zillow, Realtor.com, Facebook, Craigslist, NextDoor. This IS ABSOLUTELY CRITICAL. Don't leave any possible avenue uncovered and almost all of it is FREE. I do spend a little extra to "Boost" my posts on Facebook so people in the area will see it on their feeds. Make sure your photos are excellent! I can't tell you how many investors put bad photos on their listings! Makes mine look better though, Lol...
However, in the Denver Metro area where I've been working lately (prior Southern CA) - I find that the buyer's market is shifting to a split market. Our seller's agent agreed to 2% fee if she finds the house for us, and for repeat business. At this point, however, our business has been losing $ on the last couple flips so I am preparing to get my real estate license finally, after 13 years of buying/selling properties without one.