I like my Chirp wheels (I got the set of 3), and I will keep them and continue to use them. But I wanted to love them. Like many people, I sit at a desk all day, so I need to stretch my back. But my back pain tends to me in my very lower back (near my sacrum) or in my very upper back (just below my neck), and Chirp wheels are optimized more for your mid-back. I like having them because they serve as a visual reminder to stretch my back, and they do help stretch my back when I use them for a few minutes at night before I go to bed. But since they are not optimized for the specific type of back pain/soreness/tightness I tend to get, they are not the life-changing purchase I wanted them to be. However, I lent them to my roommate once, and she said they get to exactly where her back pain is, so I think my experience is unique.