Just received these CW-X insulator tights and tried them on a run today. Currently, it's late winter in northern Utah - so it was around freezing with some rain/sleet mix. These compression tights fit very comfortably and provided sufficient warmth.
As a size reference: I'm 6'4" ~190lbs with a 33" waist and 34" inseam. I went with XL after consulting the size chart.