In my case the gimbal did take the full impact and broke off without even damaging the breakaway parts. The bad thing was that it got squashed between the copter and the ground bending the vertical arm inward and cracking the ball shaped camera housing. All in all still not expensive (approximately €20 in parts) but a time consuming repair which can definately not be done in the field.Gimbal repair kits are very cheap, and yes the camera is designed as a break away intentionally. This way you only have to replace the gimbal connectors, and any rubber grommets you might have lost, and you save your camera. I think the kit is just $20. I bought one just to have some spare parts in case such a incident occurs.
I did do a mod to keep the rubber dampers in place in case of a crash. I replaced the pins with cut off cable ties. Just insert a thin cable tie through the hole in the rubber damper and slide another one over the end. Cut of the excess parts and you're done. Don't do them tightly, leave some slack for the dampers to move. The original pins break off too easy risking the wiring of the pan motor to break off in a crash. This is in my opinion a risk which can be avoided. I'd rather have it break of at the slide connection. Much cheaper and easier to repair.