Depending on the type of compensation offered in MLS, it could potentially turn off buyers agents, although it should not. What I would be asking myself in your situation is "What is this Flat Fee MLS Service not going to do for me that a real estate agent can?" A lot of times you will not get as much exposure through this type of service. Before you make up your mind I would interview a couple of agents before you make a decision. It doesn't hurt to get as much information as possible and it won't cost you anything. When you are buying your home you want the right person, agent, or company that will bring the best outcome for you the seller/client!