hear hear re spider webs, for some reason when I hiked along the columbia gorge the entire trail was filled with huge spider webs right at head height all along the trail, so adding a bit of swing to the trekking poles each time I planted them provided a nice break from spider webs in face and hair, though of course I try to not mess with them too much, nice webs.
One problem with trekking poles is actually kind of serious, and it's something younger non users will sorely regret when they become older users, if you use trekking poles fairly routinely your knees will probably do much better when you get older, but if you wait til your knees hurt and ache to start with them, it's too late by then.
If I could go back and do it all over again, I'd have started using them in my 30s, my knees would thank me today.
In terms of using them or not, one thing I can say for sure, if you use them, train with them before hand for enough hikes for your body to feel fine after a very long hike, your upper body is used a lot if you use them right, which I believe many people don't, you basically become a four legged creature when you use them well, which is fun, particularly on very tough terrain, it's quite different as a sensation to regular hiking. On long flats or very mild terrain I don't use them usually, just carry them til I get to non flat terrain. But uphill/downhill/streams/difficult/sketchy/precarious terrain they are great. But I don't generally hike much flat terrain in general so it's not an issue, if I did it might be. I feel like a crab using them at night going down steep sketchy terrain, I could never get down that type of thing without them. If you do try them and get that crab feeling, you are probably starting to use them right.
If you are very fast, by the way, on flats they make you faster, but if you are going pretty slow, they don't do much, that's what I've found. They are similar when used properly to cross country ski poles in terms of motion, action, and engagement of entire body, and I always go faster if I use them than when I don't, but I also grew up cross country skiing so it may be something that was taught re motor memory at a very young age that isn't easy to learn, I don't know, the second you hit the trekking pole stride though you know it, and if you don't, you will find them irksome. Going downhill they will save your knees period.
The straps by the way are so you don't have to carry them with every lift, some people cut those off thinking to 'save weight' but they actually end up carrying far more weight every day because they have to lift the pole each time they plant it, with straps you just push it forward and let it fall, there's almost no weight at all when used properly. You also don't really hold the handles, you let your wrist hang, unless you are really planting them hard like going up or down steep stuff. The only time I can see that you actually lift the pole a bit before pushing it is when you are going uphill, otherwise you basically just push it into a pendulum swing, and then let it fall. Very little weight is involved when you use them right, but if you use them wrong, you have to lift them each time you plant them.
