Serrated vs plain edge? There are plenty discussions on the internet about this topic. Here’s my rule of thumb: Serrated edges are better for slicing and sawing through harder materials (tree branches, seat belts etc.); plain edges are better for stabbing, clean cuts and push cuts (meat and whittling wood etc.).
I’ve seen serrated edges do badly against softer materials (blankets rolled up around a broomstick), which makes me nervous about using them against clothed targets. With the blanket test the serrated knife got clogged up with the material. It didn’t slice through so much as it ripped through the material.
But I’ve also seen sharp plain edges do badly against harder materials (e.g. polypropylene rope). Maybe it’s just me, but I’ve seen a plan edge blade just slide right off what I was hoping to cut.
If we look at seat belts as an example, the difference seems to be that serrated blades “bite” into tougher materials easier than plain edges, but once they’ve bitten, plain edges often cut just as well as serrated ones.
So what do you need? I’d say for cutting steak dinners, a sharp plain edge. And for cutting your seat belt/rope/rescue type jobs, go with serrated.
Putting it another (generalised) way, rescue requires serrations, surgery requires (sharp) plain edges.
I’d advise reading Knife-Depot’s article on the topic. Between plain edge and serrated they have a very interesting third option. I’ll be experimenting with this third option to see if it gives me the best of both worlds, with none of the limitations of either.