There are 2 fifth wheel saver concepts.
One is the Blue Ox and it's pretty spendy - like $250. The nice part is that this is automatically engaged and is always there to catch your fifth wheel. The downside is the price and extra weight that it adds to your hitch (if you're like me and it comes out on a fairly regular basis).
The other is Butch's Fifth Wheel Latch kit. The nice part is that it is much cheaper, like $50. The downside is that it takes a step to engage it and slide it across the open part of the hitch head.
I know we have members with both. IMO, most fifth wheel drops are a result of user inattention and forgetting a step in their hitch up process (vs. an actual mechanical failure where the hitch fails in some way).
Personally, if I opted for a fifth wheel catcher it would be the Blue Ox since it's always there and always enabled.