Welcome to yacht racing where no-one (almost) is happy with their rating. Every boat has its conditions and that is the primary reason why handicaps vary. Light air boats will rate higher in Long Island Sound than San Francisco. C''est la Vie. The other thing that PHRF considers is empiracal performance, you win a lot-your rating goes up-oddly you lose a lot they rarely go down. IMS-which is now dying, was a very accurate rating system with Ratings that changed based on wind strength and DIRECTION. There are ways to lower your rating, but unless your Dennis Conner (Dennis the Menace was a good article in yachting about PHRF optimization done by Conner). I agree with another respondent, sail fast in the right direction consistently, nail your boathandling and sail handling skills and you will win races.