I wondering about getting one of those today. Do they travel securely on the back?
I'm going to say "yes and no".
Mine is now attached to the camper spare tyre, and is not going anywhere.
When I first put it on, I had hooked it up and adjusted it tight, but it nearly fell off on the way home from a trip. My theory is that the weight of the rubbish in it had worked the straps ever looser, until it way about to end up on the road. Another kilometre or two would have seen me scratching my head when we arrived home, wondering where my rubbish was.
Long story short - don't trust the buckles and tightening like they from from factory - tie it on nice and strong and tight and you'll be fine.
Ours lives on the back of the camper too, and it's in a perfect spot right next to the kitchen. I don't doubt the big name canvas ones are better quality, but I figure for something that's going to get rubbish juice leaked all over it, cheaper is better. I don't know how long the little zips that hold the base on will last, but I figure we'll cross that bridge when we get to it. My plan is just to sew the base up if it does let go.
Good luck!
Matto