My daughter took this class this summer. It was pricey, but worth it. She just turned 2 last month and I wish I had her in the class the summer prior. She didn't fight the lessons but would have been more at ease if she were younger --> or older. The lessons were 20 minutes, 5 days a week for 6 weeks. There was a 3 year old girl who took the class right after my daughter and took to the lessons very quickly.
We have a pool in the backyard and I am greatful that she isn't scared of it, and if she were to fall in she would know to float until she is scooped out. She's too young to grasp the 'roll-over-find-the-wall' concept of the class. We plan to take her to a refresher course next summer.