Light enough to make a difference from running in cross-trainers, but plenty of support.  This isn't a "micro-light" shoe, but its not supposed to be.  For me at 6'4" and 215 pounds, running about 20 miles a week, it was just what I needed to keep ankles and knees from hurting but give me enough spring and weight reduction that I felt they were worth the purchase.  I would certainly buy these "Best Update" (Runners World)award winners again.