The biggest difference is carrying the 20-30lbs of gear that kicks your butt. The shooting part isn’t necessarily difficult until you have a 180-200 heart rate and are not thinking clearly as a result. Heck I’ve done a bunch of these. Only had 1 match I shot cleanly. Most folks will not be able to shoot it without a Dnf on at least 1 stage if not multiple stages.
The winner is rarely the fastest guy on the run, it’s the person that shoots the best and has a decent run time.
At this point, I'm just going for a finish and not dead last, lol!