Straight out of the package, they looked tiny and I was concerned. But they went on really easily. I moved around and they didn't slip. I don't know how they would hold up to a work-out, but I don't think I'll have to jerk them up throughout my normal cozy day.They aren't "buttery soft" or the kind of compression material that slides down a lot. Nothing stupendously comfortable about the fabric, but no complaints either.They're actually a little thinner than my Old Navy compression leggings that I got a year or two ago, but I prefer that. I think it'll help them move with me better.On to the sheerness test! The photo of just my legs is what really concerned me. It looks like you might be able to see straight to my skin. But 1) I was sitting in a position that highlighted it, 2) I was in lighting that emphasized it, 3) it looks worse on camera than in real life, and 4) I just couldn't see my underwear through them. (See my update below. After 2 months, they were see-through)That's right, ladies and gents! I wear some pretty baller underwear (aerie boybrief sunnies). They aren't perfect in the no-show department, but they're pretty good and keeping to themselves (and they feel like angel kisses). I do have several leggings that still show a slight pantyline with them, but I bent and twisted and just didn't see it in these. I even bent as drastically as I could, more than I ever would in real life. That time, my husband said he could see a pantyline, but he couldn't see the color of the underwear, so I call that a win!I'll update later of any issues pop up after wears and washes, but, as of now, I say go for it!Update: I've had them for 2 months and they are now see-through. I had them on over yellow fleece-line leggings yesterday and I could definitely see the other leggings through them in tighter areas (like around my knee). I am a thick girl and I did wear them regularly, so I give them credit. I wore them about 2-4 times a week and washed them after ever 2-3 wears. I may have dried them once, accidentally, but usually air-dried. I probably washed them about 10 times, give or take. How long should we expect our leggings to stay opaque? The pilling in the thighs isn't significantly worse than a month ago. Definitely there. I'll continue to wear them over darker fleece-lined leggings, mostly because the compression holds in my jiggle and they can withstand my puppies' paws better than other fabric.Previous Update (After a month): I've worn these several times now. I say you have about two days of normal activities (I wore them under other leggings at work or alone around town) before they stretch enough that you'll find yourself pulling them up from time to time. And it does look like the legs are slightly more transparent after a wash or two, but the butt still seems alright. There is some pilling in the thighs (as you can tell from the photos, they do rub together a lot). I knocked it down one star just because I think they should hold up a little better for a little longer, but they're still my favorite leggings that I have. Full disclosure: I am a little nervous about the transparency and pilling spreading. I guess I'll update again if it happens