Hey Rhonda, I was about to post this on your other thread and decided not to. Then I kept reading the boards and saw this thread so now I have to give my input. I don't like that ab roller thing. I had a similar one years ago and it was so stupid that I was embarrased I ever bought it. I see them at garage sales all the time. Admittedly I know nothing about this particular one, but it looks so similar that I would really hesitate.
On the topic here, I also don't have a clue about Core Secrets, but I LOVE, LOVE, LOVE my BOSU. It is difficult to describe how it is not a "gadget" and yet is the coolest gadget. You truly use all your own body, but it gives way more extension to whatever you do with it. The bomb for ab work!! The other thing is that is is so darn fun for cardio. There are a number of threads, including all of mine when I was deciding to purchase it, that have more on this. I will say that even after a more than a month of using it I am still just as excited about it. I also have yet to read one thing from someone who regrets buying it.