BH-55 series are supplied with a pouch, which protects it and whatever else is in the checked luggage. I don't know if the smaller heads are similarly equipped. Tamrac lens pouches of appropriate sizes are fine for the Kirk BH-3 and for the A-S heads in the luggage. I put the heads on at the destination and take them off before returning the rental vehicle. I do so only beacuse it is easier to travel and pack, not because I am concerned about the heads. IME most tripod head damage usually occurs accidentally when a tripod falls over onto a hard surface.
BH-55 series are supplied with a pouch, which protects it and whatever else is in the checked luggage. I don't know if the smaller heads are similarly equipped. Tamrac lens pouches of appropriate sizes are fine for the Kirk BH-3 and for the A-S heads in the luggage. I put the heads on at the destination and take them off before returning the rental vehicle. I do so only beacuse it is easier to travel and pack, not because I am concerned about the heads. IME most tripod head damage usually occurs accidentally when a tripod falls over onto a hard surface.
I strap it to the back of my ruck sack and pop the neoprene sock that came with it on top (I trimmed it a bit as it was too big (big job that was). It has bashed edges and scratches and stuff but nothing that affects operation. They are pretty robust - my only worry would be scratching the ball head but as long as you transport it with the head upright it shouldn't get damaged.
I don't coddle my BH-40, but I don't bang it around either.
It's picked up a few scratches, but no problem.
As far as transportation is concerned, I usually keep it separate from my tripod in my camera bag, kept in the neoprene sack it comes in.
My tripod is usually strapped to the outside of my camera bag and with the ballhead, it would stick out too much. I keep the ballhead attached to my tripod on my bag when moving quickly or wanting to set up more rapidly. Even then I may keep the neoprene sack around it. Keeps it from getting banged around too much when I toss my bag around.