HiLifts are a dangerous tool, but it's one I consider a trade-off. There are circumstances where it is the worst tool for the job and others where it is the best tool for the job. If I can get away without using mine and instead use something like a bottle jack, I do so. However, there are times when its capabilities are second to none, so I can justify the extra weight and space it requires.
I've watched where they have let loose, even when the person operating them did everything "by the book". Sometimes a pin doesn't fully seat due to a little dirt, sometimes the vehicle's weight shifts for one reason or another... anytime you play with that much weight on that small of a lifting platform, things can go wrong. That's why I consider jack stands and wheel chocks required accessories for a HiLift. The less time the jack is supporting the vehicle, the better.
When I lived in Florida, I kept my mechanism separate from the jack, well-lubricated, clean, and dry in an ammo can inside the vehicle after seeing what the salt air was doing to the pins. When I lived in the desert, I didn't worry about it too much and just periodically cleaned or rebuilt it. Now I keep mine bolted upside down on my jamboree rack, with the mechanism covered in plastic and a canvas bag. Different environments, different approaches...
