They only work well for branches about a thumb’s thickness across. I really prefer working with little hand saws that you can fasten at the end of a long handle.
I tried ratchet pruners before, and it’s quite neat but they often can’t hold in the long run, even the more expensive brands. I think it’s because there’s so much pressure and leverage. I went the ratchet way to prune my bougainvillea hedge and after a year they were dead. Bougainvillea is a hard wood but not particularly so, so I was a bit disappointed because my expensive ratchet pruner wore out after a year. It was nice and comfortable though, but I don’t want to buy a new one every year!