From my very limited experience with them -
Axial = jeep - easy to build, common, huge range of capabilities, cheap to buy and cheap to fix, huge aftermarket and knowledge database.
Losi = Rover - expensive to buy new, cheap to buy used, hard to break in and hard to keep running although they do have their fans. Kinda exotic bits, but those parts can be finicky.
Berg = Comp buggy. Nothing about it is street worthy. Built for one thing. Does not resemble a road going vehicle at all. Parts are expensive, but very durable. Lots of stuff is custom made or DIY mods.
Traxxis = Full size domestic trucks. Common. good for what they do, but really have no place on the rocks. Too big. Wrong power range. They can do some things because of their wheelbase and power, but not fun to wheel with one of the above. Good to blast around at full throttle on open ground.