How to quickly differentiate a great realtor from a mediocre one?

[Gabriela Herrera]

I am actively looking at the market to see where to invest next. I did not have a great experiences with realtors in the past. They all seem great at the beginning but then it looks like I am the one doing all the work and they only set up the visits to the properties. 

How do you tell which ones are the keepers without wasting too much time? Any questions in particular I should ask during the first meeting? Red flags to look for?

Appreciate the help!

Gaby