I ordered Sheec, Hue, and Ecoland liners to try out. Originally, after seeing these, I decided to return them because they cost more and didn't appear to be of any higher quality than the other liners. I decided to go with the Ecoland liners, but after noticing they are visible at the edges of my lower-cut flats, put on the Sheec liners after all. I found the Sheec socks impressive enough to set aside my miserly ways:

1) they can't be seen in even the lowest of low flats, including Big Buddha One flats which have a very low-cut sides.
2) after wearing the same shoes with Ecoland liners all day and switching to the Sheec liners before going to dinner with a friend, my feet somehow felt more comfortable.
3) the elastic fit snugly and the liners didn't budge even a tiny bit after walking many blocks.
4) despite its hold the elastic was super comfortable and when I took off my shoes at the end of the night, I was surprised to see these babies on my feet since I'd forgotten I was wearing them.
5) I thought the grippy bits under the ball of the foot would be annoying, but they actually seem to provide a tiny bit of cushioning.

Caveat-- as other reviewers mentioned, these may run small. I wear a size 6 - 6.5, and the "fits 5-9" size is just right. I'm not sure how well these will work for feet larger than 8-ish, as my feet are near the small end of the recommended sizes and the fit is snug. Also, since I've worn these only once, I can't comment on their durability.

Additionally, the order came with a $2 coupon for purchasing the Sheec 4-pack, which I plan to do-- with the coupon, these liners cost only $1/liner more than the Hue and Ecoland ones, and suit my feet much better.

**EDIT: Downgraded my rating from 5 to 3 stars. It's been two years and these are not holding up that well. I originally bought 7 pairs of this type of socks from 3 different brands: Sheec, Hue, and Ecoland, in addition to a few pairs I already own. I keep the socks on rotation and wear them all about equally. After about 6 months the Sheec socks developed holes in the toe area, and now after a year only one pair was still useable. My Hue and Ecoland socks have all held up and are still useable 2 years later.