I have a Yakima Rocket box and a Basket Case that I use with 2 load bars.
The box usually gets clothes, sleeping bags, pillows and a few folding chairs. The basket may get fuel, water, or a Action Packer with kitchen stuff in it.
Have you carried any fuel or water on the Basket Case? I was thinking of a jerry can or two, securely strapped down of course, but was wondering if that rack is sturdy enough.