Yeah, the 2.5 gallon (10L) cans would be nice if you can find them but they're harder to find than the 5 gallon cans. It would be great though since I could still use my rack but would have to shorten the part that clamps the Nato cans onto the rack. I also like how well the Nato cans actually seal and have replaceable gaskets. Not so sure about the rotapax units since it's a plastic opening and getting a good seal may be problematic.