Do they work? Yes they do. But they have advantages and disadvantages like anything else. Having used them I found that:

Their big advantage is being able to get into and around logs that straight bladed saws either cannot reach or have an obstruction that prevents you from getting a proper sawing action.

Disadvantages are: Require more effort. Slightly more prone to trapping and kinking in use. More likely to break.

I should tell you that those are not major issues. The advantages outweigh the disadvantages.

I would not use one as a replacement for my Laplander but rather as complimentary to it.