+1 on straight edge for the general outdoor use, and easier to maintain that edge in the field. Serrations have their place and uses as well. I know a LOT of First Responders who carry a partly serrated or fully serrated blade for cutting seat belts and other tough materials. A serrated blade might also be useful if you cut a lot of rope or webbing on a daily basis. Just like a lot of things, it just depends on where you are and what you do (or expect to do) with the blade. If you think you might need a serrated edge at some point, consider a folder with a serrated blade, or one of the multi-tools that include a serrated blade (leatherman wave comes to mind). YMMV

Usual disclaimers apply.