I tried these on in a store and found they run a little large - I usually wear a size 10 or 12 in jeans, and the medium in these leggings fits perfectly.  The waist does come up high on me, but I am really short in the torso - I never wear shirts tucked in at the waist, so the high waist is not an issue for me.  The length is perfect - I'm about 5'7" with a 33" inseam and they are just right.
I really like the styling of these - the top-stitching looks like real jeans, but they fit and move with my body much better than denim.  These are not denim, but look so much like denim, people think I am wearing really fitted jeans.
I like them so much, I'm getting two more pairs, as well as two more pairs of the corduroy leggings. I wear them with sweaters, tunics, or un-tucked shirts and boots and they just look great!