There are a few guys that "blow smoke" so to speak. I think you have to talk to other racers and see who they use,and what their real impression of a builder is.
Word of mouth is still the best advertisement,but you have to be careful who you listen to.
One of the problems with relying on that,though is that it does not draw to a very large crowd. I know a very good builder that relies on word of mouth advertising and a lot of people have never heard of him. He stays busy,but could easily get more work by advertising.
Keith