Hi Amy,
My family is staying at Old Key West in April, and have been there before as well. I think you will be very happy you chose it. The one and two bedroom suites are HUGE and the studios are a good size as well. The suites have a full kitchen and the studios a kitchenette, which are very convenient. The pool was recently renovated, and absolutely beautiful. There is a huge slide and a bridge that overlooks the pool. There's also a sand play area (not for older kids, I know, but I wanted to give you a sense of the area.) The resort is very large. It is actually the original Disney Vacation Club property. There is a bus system that runs throughout the property, with stops in a variety of locations. This convenient because you don't have to walk to one central spot to catch the theme park buses. As for waiting times, in my experience, waits are consistent with those at all of the properties. I never waited more than 15-20 buses (and that was when I saw a bus pulling away as I was approaching). Old Key West is a great place for older kids who are interested in going to Downtown Disney and enjoying the shops, dining, etc. There is a lovely boat launch that makes getting there very convenient. Access to all of the theme parks is via bus.
There is one full-service restaurant on property - Olvia's. The key lime pie is yummy. There are also locations for quick service by the pool area. There is a great seating area that overlooks the water where your kids can enjoy their food. There is an arcade and other activities for kids of all ages.
If you are interested in seeing photos of the resort, you can visit
www.allears.net and search "accommodations" and then pick Old Key West.
Have a great trip!