I have mixed feelings about Pilates. It can be helpful for people to learn how to strengthen and use core muscles in a new way. It can also be very hard on the hip flexors as you are put in many positions with the back flat on the floor and legs straight at an angle. Most people are not made to do these exercises(especially tall people)and it can place undue stress on the hip flexors. Lifting one straight leg at a time and then switching legs(scissors), can also strain the hip flexor.
They also use strange, vague words and phrases to sell Pilates like becomming "supple" and "toned" or "lengthening the body", which I find misleading.
That being said, I think Pilates can be much like Lumbar Stabilization programs where you learn how to find your "neutral" spine and use your body in accordance with that position. This can be very helpful for people who have lower back pain or weak abdominals.
I'm not sure how Pilates could be a weight loss workout because your HR is rarely elavated for more than a couple of minutes at a time. I've attended many Pilates classes and will actually become certified to teach level I pilates this weekend. I'm doing this because I think there are some useful thing to be learned in Pilates and could fit in as a part of a good exercise program.
Carolyn