I think the most important thing is to take this show with a grain of salt. Don't forget, no matter what, this is still a T.V. show that needs rating in order to survive. Maybe he already he studied the maps beforehand and already know which way out. Maybe there's a helicopter radioing to his crew to have him go through a certain route. Maybe the crew feed him real food off camera. Maybe he sprained his ankles a few time during each episodes and sit out for a few days in between. Maybe he has stunt double. Who knows what's real and what's not. I have to give him a lot of credit for the things he eat (again, this is more or less for dramatic effects for the audience). I could believe he sucked the juices from the elephant dung.
The most important thing is to remember as much of his advice as you can, and during a real survival situation, assess your own capability and do what you can. I highly doubt someone without his agility will even attempt to climb a tree that's 100 feet high. (This reminds me of the superman halloween costumes I had when I was a kid and on the box it labeled "do not attempt to fly"). I personally find his show very entertaining and somewhat educational, and I combine what I learn from Bear Grylles, Les Stroud from Survivorman and all the other books I've read on wilderness survival.
Getting back to knives, I question his choice of knives, but that's just me. Maybe he's trying to mimic a real world hiker who's stranded in the woods with an average knife (and who happens to be parachuting his way in, and able to use his parachute cords).
* I know he uses a titanium dive knife, which is really good that it doesn't rust, but it's too soft for survival purpose (well, he did beat it up to death ... with a rock).
* The Gerber Gator he uses doesn't even have a thumb stud or hole for one-hand opening. I don't have a Gerber Gator, so I don't know how easy it is to open with one hand
* Some say he used a MOD ATFK on his Moab Desert episode. I re-watched it and it doesn't seem like a MOD ATFK. I have that knife and it has a spear-point blade, while the one he used in the episode is more of a clip-point blade. I heard it might be Buck Iceman, which seems to make more sense since the knives he used in all episodes are not too expensive