DON'T FORGET ABOUT THE DDE/TIW CARD!
This factors very heavily in our calculations. We feel our break even point is 7 days since we eat at a TS at least once per day per trip. And on some trips (like when we travel with family) we get much more than that out of the DDE card. It's also good at places like Artist's Palette and the Beach Club Marketplace. And all alcohol.
So, with the $100/$125 discount per ticket, add in the $60 for the DDE, then subtract 20% from a significant part of your dining bill, it adds up fast. And we like to use it when we travel with family (we are travelling with 11 in Feb) which is a nice perk (you can use it for up to 10 people).
There are other perks we've gotten (discounts on rooms,
DCL onboard credit, discount on water parks, etc) that we just consider that--perks--that don't figure in to our calculations. We like the freedom we feel we have with the annual pass and not having to worry about using parkhopper days *effectively* to get our money's worth.