Should I hire the Cartersville agent who has already sold the most units in my building?

Selling the most units in a Cartersville building can mean an agent knows that property well, or it can mean they represented the builder and are used to negotiating in the builder's favor rather than yours. Ask directly whose side they were on in those past sales and whether they can represent your interests without a conflict from an ongoing relationship with the builder. A track record in the building is useful information, not an automatic reason to hire someone. Joel Boss will tell you plainly if a conflict like that applies first.