A fixed blade design is inherently more durable and reliable than a folding design. That's not to say there aren't some strong folders out there, nor are they any less capable. It's just that a folding knife is usually a compromise compared to a similar fixed blade. A fixed blade also has the added advantage of usually being easier to clean than a folder, making it better for food prep or dirty jobs.

Therefore, a fixed blade is usually the way to go if you have the ability to safely and legally carry/use one.

Personally, when I can, I like carrying a multi-tool (like my Leatherman Charge) and a fixed blade. The multi-tool does most of the little stuff like a pocket knife would, while the fixed blade does the heavy duty stuff. I also usually carry a small folder like a swiss army knife just as a backup or if I might need to do something that would destroy the knife.

As far as the Kabar goes, they're pretty good knives and a classic design, but not really my favorite for a woods/survival knife. The guard on top gets in the way (though that can be ground down) and I've had the handle fall apart or break (the tang design is the weak part of the knife). I would stick with the SRK, but like I said Kabars are proven field knives, so chances are you wouldn't be disappointed if you really like the design. You could do much worse.