THE STABILITY BALL
I went ahead and did a side by side comparison workout with my stability ball and "The Bean."
Abs crunches- All abs exercises were pretty much the same, as far as execution. The Bean might be good for someone who has balance issues, but other than that, everything was the same. Like with all exercises, if you don't squeeze the muscle/area you're working on, it's not going to do anything.
Glutes exercise - I did the exercise where you lay your back on the bean, with your rear-end as far off the end nook as possible, extend both legs, feet planted firmly on the floor, and push up with both legs, squeezing the butt, then back down again. I was able to do this same exercise with the stability ball. I did like this exercise better on The Bean. I felt like I was too high off the ground with the stability ball.
Push-ups - Knees and calves on both The Bean and stability ball, upper body supported by arms, and hands on the floor for push ups. The Bean made it easier to do this exercise, but I think the easier part is because I was down lower to the floor. It was more challenging to use the Stability ball, and I felt like I got a better exercise with the stability ball.
Back extensions - Flipped the bean over for this one, lay stomach side down, feet on the ground for support, hands behind the head and bring the torso up and back down again. For the stability ball, pretty much the same, but I had to anchor my feet under a piece of furniture to keep my feet down. I liked The Bean for this exercise. It felt like I had better extension.
Side kicks - Again, The Bean flip side over, lean sideways and bring the leg up to the side and back down again. Same with the stability ball. Not a lot of difference, unless balance is an issue.
I did a total of 6 sets of 20 reps for each exercise, alternating between The Bean and the stability ball.
I guess it depends on perception. They come out about equal, seeing how I did prefer The Bean for some exercises and the stability ball for others. One isn't better than the other, they're just different. I haven't tried all the exercises yet, so time will tell. I will, however, keep The Bean in my arsenal of workout equipment.