We've never done Tom Sawyers island...for lunch or just to visit it. Our kids have, but with our babysitter. In MK, if it's off peak hours, we eat at Cosmic Rays. If it's peak, we usually go to Tomorrowland Terrace. How long does it take you to actually get to that spot at Tom Sawyers island (assuming you're starting at the entrance to it)? Is it quick/easy access?