I bought a chain drowner to give it a try. Seems ok, but does anyone see a real advantage to using chain for a drowner instead of, say, cable/fiberglass/or rebar?

Chain does not twist or cork screw therefor easier to reuse. Not as heavy as rebar and can easy be thrown from bank to deep water. The double loop chain also helps in non return of the drowner slider lock.

Also, if you dont have a feedbag or cant stake the bottom end, you can always rig the chain as a long chain system for beaver.