I wear them most of the day every day, but not (so far) when I'm riding or walking in shorts. A couple of years ago I had a basal cell carcinoma and some actinic keratoses (sun-related skin lesions) removed from my shins, and the surgeon noticed some swelling around my ankles. he pulled up his pants cuffs and showed me his support socks. On his recommendation, I ordered a few pair from Ames Walker (www.ameswalker.com, i think). They've made a big difference in my leg and foot comfort, and reduced the swelling to the point that it's not noticeable.
I don't wear them cycling (purely aesthetics--I will when the weather cools off enough for tights). But they're so comfortable that I've almost stopped wearing shorts for hiking and working around the yard, so i can wear my old-man socks.
Walmart usually has them cheap, but I wear size 15. The doc says Ames Walker is the place to get them.