I have a pair from REI made by Leki. They're fabulous, for all the reasons indicated. I also have a 3rd identical pole (long story, but let's just say that Leki stands behind their products!) that I keep in my truck so that I have a good staff available should the need arise.
This past summer, I loaned #3 to a friend with a bad ankle as we bushwhacked to a cliff in S. Ky to rappel. Afterwards, he swore that he wouldn't have been able to make the hike without the pole, & has started shopping for a set for himself.
I'm continually amazed at how helpful they are whenever I use them. Are they a bit of trouble to manage? Sure, at times, but so is my 5 foot hickory staff. Are they worth the trouble? Abolutely!
David