I've found they work best when you have a PH and a tracker. Or I suppose two trackers. One tracker has to quickly set them up for you. Or the PH could do it as well, except sometimes the PH should be concentrating on the game especially when you the client are unsure which animal is which and which to take. Hunting by yourself they are difficult to use quickly.

Also I think the extra movement often spooks game so a quick shot as soon as possible afterwards needs to be taken.

My first safari I did not use them but did on the next two.

However on balance I do like them, especially in Africa.

They allow a much steadier shot than off hand. Also there are some places even where hunting by oneself that shooting sticks of some kind are needed. One example I know of is a place I sometimes hunt fallow stag. It is flat low land country with lots and lots of small bushes for the deer to hide among. A human walking along sticks out but the deer are hidden. No tree or similar is possible for a rest and the bushes are twiggy and too weak to use as a rest. Off-hand shots of 150 plus yards are often needed. Getting closer to the deer almost always spooks them. A good place for this sort of portable rest.