I am not sure what Gerber makes there machete out of. I am gonna assume 1050-1055 because of the flexibility.
First I am not expert this is my opinion, but my friend makes knives axes and this make some sense to me.
Price sure as hell doesn't mean quality and name brand blades doesn't mean they do everything well....
Machetes, I get it to chop things, and then I can also use it for a weapon. If that isn't your goal, go buy a sword....
Like others said 1095 O-2(or is it 02) steels are hard keep a edge and don't flex That means for a good chopper you are going to need a thick blade.
Here comes Kabar with a very heavy (which is great for axes....) blade. While its a good weapon metal frankly I don't get the metal they are using. Also most people wont abuse the blade just for the price. Although I will quickly admit the grip is fantastic.
As for Gerber, I am not impressed at all, I'll skip it since I haven't played with.
Coldsteel - I have owned one gave one away, bought a friend one. Here is the deal, the grip sucks. You need a dremil tool or something similar to finish it off. Sandpaper would work great as well and is needed. However its flexible but still retains its blade pretty well. It works like a machete, cuts like a machete, easily sharpened like a machete (unlike Kabar just due to surface length can be a chore).
I have slammed them into plywood and stood on the blade, to climb up on shipping containers. Thrown them etc.
Here it is being abused for our amusement overseas. We threw this thing over and over and over. Great blade for the price!
Don't expect miracles but you can't beat the cost.