I bought these to wear for a party and realized that the back runs lower than the front!!  Unfortunately I found out as I was leaving the house and could not mk a change.  Needless to say if you are thicker in the rear or tights expect to wear something over them or you will have a night of pulling and pulling or sitting down in a chair with your rear to the wall most of the night.
I loved the look though and got many many compliments on the leggings.  just have to make sure I modify by using something over them to hold them up next time, i.e.short shorts or use as just a tight.