Sport England - Sports Facility Calculator - Public forum - Planning Advisory Service (PAS)

Does anybody have any recent experience of the validity of using the Sport England Sports Facility Calculator in estimating financial contributions for indoor and outdoor sports facilities, to be included within a s106 agreement for residential development? In the case I am involved with the LPA is using the Calculator in the absence of a PPG17 study but with a general Core Strategy policy, no Planning Obligations SPD and a vague Development Brief for the site, which is non-specific on the contributions. Is anybody aware of the Calculator being tested on appeal?