I'm a Jeeper, a rock crawler. I carry a high end "Hi Lift" brand jack on my roll cage... I've used it, and I don't like it.... But I carry it because there are times when it's flat out the only tool for the job.
Any day that your pulling out a Hi Lift is a really bad day. Off-road folks use it as a last resort tool only. They kill people, they hurt people, they damage vehicles and equipment. But, I would not go into the rocks without it, because when things go totally sideways on you.... You may need it. Bad.
Always fear the thing.