Mark: We did the same sort of thing with the van in NZ, a package of linen and not having to refill the LPG from memory. It also covered the diesel tax that is payable per kilometer in NZ.
YCF: I don't know that we scratched or chipped the paintwork on our van, but we certainly didn't take photos of the condition of the van. When we returned it there were probably four or five others returning theirs as well. The chap checked that the toilet was empty, the fuel was full, took the odometer reading, returned the GPS bracket that I left stuck to the windscreen and we were off...
All in all we had a great experience, and paying the extra insurances was very much worthwhile. Not only peace of mind but it just made the drop off so much more simple.