They're okay... warm enough and relatively comfortable, but two big drawbacks.
1) Awkward fit and seams, particularly in the crotch. Other than the inside tag (which I took off, super itchy) there is no distinction between which side is front and back. Any amount of booty will cause the the back to dip uncomfortably low.
2) Major off-gassing! They're synthetic, and I made the mistake of wearing them straight out of the package. I was followed by a cloud of fumes all day. Even after a wash, I had to lay them out for an entire week before the smell dissipated.
These leggings stunk badly of formaldehyde and finishing product. No matter how many times I wash them the stink would not go away. I was not able to return them therefore I had to throw them away. A total waste of my money. Extremely dissatisfied.
They look quite nice on, and are very comfortable. However they wear out quickly, after one or two washes, and they came with a strong smell that needed to be washed out, which caused them to look quite worn after one use.