The Otterboxes and Pelican boxes are bomb proof as far as I am concern. However, they are extremely heavy. Due to long portages and fly-in weight issues, I have been moving toward an ultra-light style of paddling.
Nowadays, I normally use an Aloksak to keep my small digital camera dry. I like this setup better because it is quicker and easier to use. If I am expecting a lot of mean rapids I will use my small Pelican box.
It has to be a mighty special place to get me to bring the DSL camera in that big old Otterbox.