In addition to being a Real Estate Broker, Property Manager and investor myself. I also teach real estate to Realtors across Florida. Listing agents and Buyer's agents have different legal responsibilities to their "clients" when in a sale. The BIGGEST thing that 99% of people don't know (and it is too difficult of a subject to get into in this thread, but I am happy to discuss over a phone call) is that working with the LISTING AGENT directly LIMITS your representation as a buyer. In fact, you get what is know as a "TRANSACTION BROKER". Their legal responsibilities can be read here: http://www.leg.state.fl.us/Statutes/index.cfm?App_...
BUT in short, you are limiting yourself significantly. It is absolutely against the law for a transaction broker to "look out for your best interest"...and in simple translation...that could cost you thousands!
As a young investor, I bought from the listing agent. As I grew in experience I always had my own agent and made certain I had a good one, with plenty of experience.
As mentioned in the thread above. Good agents are busy. They don't have time to run around and look at a bunch of properties for every investor that calls...that will most likely not do business with them. However, if you know what you want and are serious, the agent will work hard for you and will go above and beyond to keep your business and earn business from other serious investors.