Having recently been through the process of finding a realtor, I can tell you that there indeed are a fair number of sub-standard realtors around. As mentioned before, I went with Travis, and you can find my review of him
here. (The tl;dr version- Travis saved me more than he cost; however that involved me following his instructions and judgement.)
Some of the other realtors I dealt with had some red flags right away. Some were obvious signs of desperation such as wanting us to sign an exclusive purchase agreement within seconds of meeting them. (For 6 months.) Some were less obvious like "I don't use text messaging, and I really don't like email."
If you are looking at a realtor, and a friend tells you "This guy/gal is good"- ask them what made them "good." I had one friend refer me a "good" realtor when I bought my old house, and it only took me one meeting to see that he didn't want to do a lot of leg work. Turns out what made him "good" was that he would often go out for beer.
I would also argue against putting the value into a "per hour" basis. First of all, some realtors put more money into marketing your house. Secondly I would rather have my house sold fast and without issues than to have my realtor "earn his money" by spending weeks or months selling my house.