I'm a fan of the Pacific River Bag and have had it for over two years. Sometimes the cam straps can be a little short with a big load, but you can easily add an extention. I've seen one person flip with it and he didn't lose anything. I feel confident that my gear will stay with the boat when I have a flip... someday.
"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." - Mark Twain