I haven't really noticed any changes, I still carry a few more pounds than I would like and I'm getting pretty grey. But my dad started going grey at 17 so I really didn't have much of a chance there.
But I've noticed a lot of changes on the inside. My blood pressure, cholesterol, heart rate, and general physical fitness have improved tremendously (I play tennis 4 times a week). My doctor said that may health changes are remarkable. Physically I feel 10 - 15 years younger then my chronological age.