I can't much advice on the annual passes, but can give a little on the Silver Plan. First of all, think about some of the things you'll want to do while you're there - expensive restaurants, tours, dinner shows, spa treatments, cirque, etc. Price them out, and compare that price to their silver plan price. Each wish costs roughly $34, so depending on whether the particular thing is one wish or two, you can decide whether the plan is good for you. Also, think about splitting your 10 day stay up into two separate reservations, and adding the Silver Plan to only one half of the stay. This may save you some money, because you won't have to use wishes for things you don't really want. We did this and it worked really well for us. Here's how our savings worked out:
Hoop Dee Doo Revue -
* Price per adult $49 before tax and tip
* One wish - $34
* Savings per adult about $20
Spirit of Aloha Luau -
* Price per adult $49 before tax and tip
* One wish - $34
* Savings per adult about $20
Keys to the Kingdom Tour (includes lunch) -
* Price per adult $58 before tax
* One wish - $34
* Savings per adult about $30 (plus lunch cost)
Hidden Treasures Tour -
* Price per adult $58 before tax
* One wish - $34
* Savings per adult about $30
Cirque du Soleil -
* Price per adult $79 before tax
* Two wishes - $68
* Savings per adult about $15
Total savings per adult about $115
Deciding if the Silver Plan will work for you truly takes some planning and pencil pushing. The things that we did will obviously save a lot. Meals sometimes will save a lot, depending on how much you eat. Buffets won't save anything.
Also keep in mind, if you have children in your party, even though their wishes cost less, they are pooled together with all the other wishes, and can be used by anyone. So, for instance, it would be beneficial to use most of the wishes for meals on adults rather than children, since you're likely to save more. There's definitely lots to think about... so start planning what you want to use the wishes for, and see how the money works out.