First off, although I've day hiked for years, I'm a total newb at backpacking. I bought these poles on a whim because everyone says you should use trekking poles and boy am I glad I did. Our first trip was only 18 miles on the Appalachian but involved constant climbs and descents. However, these poles performed like a champ.
The locking system was very quick and easy to adjust and never once budged even under a great deal of weight during descents. By contrast my companion had a new pair of fancy Leki poles with cork handles and spring loaded shock absorbers (I was jealous) but the twist lock mechanism had a temporary failure on the trail before we could get it to reengage. My flintlocks were flawless.
There is a little bit of flex in the poles and I'm not sure whether that's good or bad but it was not bothersome to me. I found the grips and straps very comfortable and was not troubled by sweat.
My boots were not up to snuff for this maiden voyage so I experienced a bit of toe bang so I relied on these babies to keep me from crippling myself. Combined with the benefits of balance, stability and weight distribution (saving my knees and ankles and preventing faceplants), I came away from this trip appreciating how truly essential a piece of gear trekking poles are. These poles performed great for me and I look forward to using them on our next trip.