I had a severe underbite that most people could not see my upper front teeth when I smiled. After 1 year of invisalign treatment, the underbite is now gone and the rotated tooth on top is about 70% corrected. Lower front teeth crowding is totally fixed (very perfect).
I have gone through 25 upper and lower trays at this point and have 5 more upper trays and 1 more lower tray to go. Also, there are a total of 16 "bumps" put on my teeth.
Although it is a bit pricey, I am very happy with the result at this point.