I have been wearing the Shape Ups for approx 3 months now and I love them!! It did take me about a week to get used to them. My calves were sore and my toes would go numb also. I was also pregnant though and I had a lot of swelling. Now that I'm not pregnant...I still love them, they are so comfortable!! I wear them all the time.
I've only heard about the Reebok. I have not seen them in person, but people have told me that they have a ball in them and it moves around when you walk or try to balance. They sounded more difficult to get used too, so I went for the Shape Ups.
I got mine at Academy and they are cheaper there than on Skechers website.