I'm not, but I know others who are. This is one of 2 options for catching a dropped fifth wheel.
The other is Butch's Fifth Wheel Latch System:
Home Butch's Services
Both catch the fifth wheel before it is able to hit the truck bed. The Blue Ox is about 5x the cost of Butch's, but the key difference is that the Blue Ox doesn't require any user intervention in order to be activated (i.e. you have to latch it after hitching up for it to be effective) whereas the Blue Ox is always there and always ready to catch a fifth wheel.
It all comes down to what you're trying to protect yourself from- a mechanical failure, go for the Butch's kit (little $$); or a mental failure on your part, go for the Blue Ox (much more $$$$$).