I am going to have to agree that getting my CFI was the best thing I ever did. I got hired into a job where all I needed was a commercial single. However, I am now doing a side job of part time flight instructing making 100% of the flight instructor fee. Got to ride in a King Air C90 all weekend to get my 5 hours PIC then gave a flight check for someone. I'm living a frickin dream and I owe it all to getting my flight instructor certificates.