Each program has different strengths and it will appeal to your own travel patterns. My work takes me to large cities and secondary markets. I usually frequent Starwood and Hyatts. (I had a great stay at a Grand Hyatt last night). I find Hilton to be fantastic in secondary markets where you will find HGIs, Hamptons and Homewood Suites. Service is always great, upgrades are always available and breakfast is always available. I have had hit and miss service at FS Hiltons. This year I have not been upgraded twice when staying at Sheratons or Westins in large markets. So look at where you are going to and look to see what is available.