I've got to admit that I'm seriously tempted by the VIP pass. My first thought was "FIVE HUNDRED POUNDS?!?!!" But I have no ability to visit parks outside weekends due to my work, and Thorpe and Chessington are a five minute deviation from a drive I do every weekend.
So breaking down the cost:
£119 - renewal of existing benefits of premium MAP (which I undoubtedly use)
£60 - 3 visits to foreign Merlin attractions, difference between MAP existijg 50% disc. and what is left to pay
£20 - unlimited drinks (I don't drink that much at parks to be honest... but I might get 10 or so over the course of a year... All adds up)
£30 - the value "to me" of having premium parking all year (on top of the included parking).
Sadly I suspect the backstage tours won't work for me, as they will want to arrange them for quiet weekdays that I can't make... So i wrote that off entirely as a benefit.
So thinking about it logically, that leaves £271 of "value" that needs to be soaked up by all-you-can-eat Fasttrack. And I wholeheartedly agree that if are self employed or have generous holiday entitlements (or the moral flexibility to take sickies ;-)), you can go mid week, have a nicer time anyway due to the place being less busy generally, and the numbers don't stack up.
But for me, I would definitely buy at least a £30 Fasttrack package every visit. So that's just on the line, having repaid for itself after 9 visits. Only "breaking even". But then you consider the other perks... Not having to queue at the park to buy Fasttrack (a miserable experience at Thorpe), not having to take the rides you don't want to do in the Fasttrack packages they sell you, and being able to do the ones you do want repeatedly, and also not having to worry about getting up early for ERT (my route takes me part thorpe at around 13:00, when it's already pretty busy...)
All this makes me think I'll probably (probably) go for it - depending on what the options are for upgrading my normal pass (which I only just bought) and whether there is a renewal discount (which would, of course, push it we'll into the "makes sense financially" zone).