I ordered and received a Cambridge Box back in Feb. It immediately leaked when set upside down in the bathtub (3-6" of water). I returned it, and am getting a Recretec. Wish I had known anyone made them out of thicker Aluminum before, you would have gotten my business. Recretec has the boxed lid, vs cambridge's shoebox style, and I think the boxed lid is a better design. I borrowed a recretec last summer (older) and it passed the bathtub test perfectly.
My opinion, they should stay dry in a bathtub when brand new, but I wouldn't expect it to be dry after a beat-down. I plan to pack accordingly.
I am a river, babe - I've got plenty of time, I don't know where I'm going, I'm just following the lines..... - "We are water" by Shaye