We've always used a realtor. I personally like having all the t's crossed and i's dotted just right. The realtor is a professional and knows a lot more than we think we do regarding the market, etc.
I did not like open houses because it is typically nosy neighbors coming through. Same with the info sheets out front at the for sale sign, mostly nost neighbors grabbing one to see how much you are asking.
Realtors have connections with mortgage companies and can make sure a potential buyer is qualified and you don't waste precious time of someone who can't afford or get the mortgage anyway.
On 2 occasions when we were selling, we were in process of building a bigger, nicer place. Our Realtor cut a deal where she represented us on both the sale and the purchase and we did $$ that way. The builder was the one who paid her commission, not us....:)
Our area has a lot of growth but I still would not call it a seller's market right now. It depends on the homes, homesites, etc. We get offers from realty companies about once every 2 months to see if we are interested in sellling because we are on a huge lot with a lot of privacy. All of the homes like us that are on the more private wooded areas sell like hotcakes because they rarely hit the market. Our neighborhood overall is very large and there is a very low percentage of homes on the market.
Good luck whatever you decide but my opinion is that it is worth negotiating with a realtor to sell your house.
ETA: I agree with Gamma.. NEVER be alone in the house with someone looking at it. There have been several instances around here where there was an open house and the realtor ends up dead or kidnapped and dead as well as valuables taken from the home.