I've owned both. The Campanion is an ill handling, difficult to sharpen inefficient wrecking bar. For the weight of one of those, you could get a longer blade, thereby increasing chopping, hacking, and slicing power, more reach (for reachin' out ta cut dem fish strings and parachute cord, of course) as well as having a longer fulcrum if you REALLY insist on prying with a perfectly innocent blade.
On the other hand the Crewman is very, very tough cuts extemely well, is a quite a bit lighter, and tends to fit mere mortal sized hands better. (As I recall all BK&T handles slabs are the same thickness, but the thickness of the metal used on the model knife can very much come into play determining the overall thickness.)
If I was gonna go out to pick a fight with a bulldozer I'd pick the the Campanion. Considering that is very unlikely to happen, I'd choose the Crewman (which is PLENTY tough, AND cuts well) and pick up an extra wrecking bar at the local hardware store with the difference.