Loc: Tacoma, Washington
I take on all walks, but usually left strapped to the pack. Went trying to power up or down hills with much of a load, I pull them out along with leather gloves. The poles give a bit of relief to the old man's legs and also increase stability a bit. They also are used for tent poles. So in my case the addition of poles do not represent much of an increase in pack weight.
Like you, I've toyed with the idea of not using them as my pack got lighter. (I used a single staff, then two poles, when I was carrying a 40 pound pack for a weekend; now I'm at 20.)
However, I find that I always take them, and that they're always in my hand. They help establish a rhythm, and they help push aside brush, or knock down cobwebs (if I see them in time.) On uneven terrain, or crossing a stream by rock-hopping, they help keep my balance - unlike Redford and Nolte in Walk in the Woods, who fall into the stream with their poles famously strapped to their packs. On downhills, they're handy brakes, and on almost all surfaces, they do help absorb some of the pounding my old knees would otherwise take.
I've used them as tarp poles, but nowadays, with two pound tents, they are strictly a single-purpose item. My current preference is a pair of Black Diamond Trail Ergo Cork poles.
I would think comfort would be subjective and dependent on the size of your hand. I use Leki poles with twist locks and composite grips. Winter for me so far, has been all ice, very little snow, the poles have saved my butt, literally, numbers of times. There's times when I don't use them, and I just bought a pack that stows them on the fly very easily. It's a help when I get to spots where I need my hands and don't have much room on the trail to take the pack off and lash them on. The only time they've done me grievous harm was on a trip in the Sierra w/mosquito clouds and a liberal dose of DEET applied to my hands was trapped under the straps of my poles. I had a major chemical burn develop and had to bail out, as my hands were swollen and on fire. Products containing DEET have a warning about putting it on under clothing, I didn't think...... duh. Friction and strong sunlight at altitude didn't help, either. Though I use a tent with dedicated poles, the trekkers have on numerous occasions served to make a cooking and eating shelter with a light 6x8 sil-nylon tarp I carry when I think it's needed. They also are good for deterring the non-friendly dogs people let run on the trail, because they're in the wilds and anything goes. I love dogs, but hate getting bit....
I have a pair of Leki Shasta poles. They have cork composition grips and twist-lock length adjustments. They weigh about 18 oz for the pair. In my opinion, if you get name brand poles and avoid extreme (wrap around) grip designs you can't go very far wrong. Sure, you can get "Mercedes" carbon fiber poles with racing stripes and other bells and whistles but they are pricey and don't work much better than "Fords".
Loc: Nacogdoches, TX, USA
I haven't used poles myself (though I have old graphite golf club shafts to make a pair eventually). I've read the Costco ones are actually really good though, if they're still available. Here's a review.
Material: carbon fiber. Lightest, which makes a big difference on a long day (you're swinging each hundreds of thousands of times), damps vibration, won't dent and not cold to the touch. Also won't corrode. Potential downside is sudden failure with no warning.
Segments: one-piece is best--lightest and strongest but difficult to stow and transport and of course, must be fitted and is not adjustable on the go. Two-piece is stronger and lighter than three or four but still large when collapsed.
Adjusters: internal expanding joints are stronger than flip locks and leave a smooth pole. Can be much more fiddly to adjust though.
Baskets: I prefer very small trail baskets to bare poles because every once and awhile a bare shaft will jam into something unexpectedly and cause all kinds of grief in a split second.
Confession: I stopped adjusting pole length on the go years ago, just set and forget. Adjustability can be critical when used as shelter poles.
I have CF from Leki and Komperdell, can't recall the model names at this point. Can recommend either brand; there are plenty others but no experience with them. Aim for 8oz or less per pole.