Picking the right Realtor to help you sell or buy a house is a really big deal. There is a massive amount of money on the line and making the wrong decision can be extraordinarily costly.
Frankly I see this all the time: wonderful people getting absolutely hosed - and in almost all cases, they had no idea that a hosing had occurred. And ALL of it goes back to the initial decision about who to hire.
Most people, when hiring a lawyer, doctor, accountant, contractor, worker/employee, or any other sort of professional or service provider, go about it in a wise way: interviewing several, looking for who has the best chance for producing optimum results, and then deciding upon that basis.
Would you hire a lawyer that you just happened to meet on the courthouse steps? Of course not. But people make a hiring decision for a Realtor based upon a chance meeting at an open house or trying to deal directly with a listing agent.
Would you hire a doctor to perform a surgery just because they're super nice? Of course not. But people will hire a realtor because they "really get along with them."
Would you hire a contractor just because you've known them a long time? Again, of course not. But people will do exactly that with a Realtor or will stay with them "out of loyalty."
Do. Not. Do. That.
Hire a particular Realtor for one primary reason: superior practices, strategies, and systems that yield superlative results. Everything else is secondary...