I just picked up one of these at walmart
Camillus Carnivorethe saw sucks, as it bottoms out about a 1/4 inch in the wood. The saw portion isn't cutting as wide as the blade is.
The chopper portion is "ok" at chopping small brush out the way or making a quick shooting stick. The blade tends to bounce off though so you have to have a pretty straight on swing to get it to cut
didn't try to dig a trench, cant imagine trying to dig with it as it'd tear your hands up
34 bucks or so at walmart I figured what the hell - might see if they'll take it back
or I might just grind off the saw portion and make it curved like a slight kurkuri - and sharpen the "digger" portion and make it a morphadite tanto kukuri