>>2576151They can be very useful for trail maintenance.
>>2576127These are the only ones I've used extensively, these ones with the extendable handles. Very useful when you need more leverage or for cutting things high up. Maybe others are better or worse, dunno, but these ones are sturdy and work well, I know that.
If imagine that pretty much all of them are pretty similar in function, as long as you're not buying cheap Chinese stuff that snaps when you try to cut something thicker than a 1/2 inch.