I have a Thule Evolution box and just love it. Fits all the ski gear for the family and is also great for extra room on those summer trips.
We roll with one of these as well. With two dogs and a baby the thing is on the truck year-round. I love it. I will be looking into a Thule rack though. I want to toss a set of J brackets up top for the kayak. Has anyone mounted a Thule box and J brackets simultaneously? i think I can get away with it if I scoot the box to one side of the Thule rack.