I purchased the Cyclus Pangolin Backpack for my wife, as she had found the item a few months back and I wanted to surprise her for her birthday. She could not have been more thrilled. She absolutely loves the ingenuity of Cyclus to integrate both style and recycling used rubber that would other wise sit in a trash heap.
As for the bag itself, it really is made of good construction. The backpack holds its shape well and will protect items inside. The shoulder straps are heavily padded, which is excellent, but the size of the backpack means the bag sits more at the center of the back than at the shoulders, so much of the strap just spans the distance between your back and shoulder, rather than sitting higher on your shoulder as most backpacks do.
The size of the bag is somewhat disappointing as it does not hold a laptop, notebooks, or full-sized textbooks all that well. The back pocket in the bag is big enough to house an e-reader, but that's about it. The organizer pockets are well-designed and easily put to good use though. The space in the bag is good, and it will hold a fair amount of items, but again, smaller or folding items (jacket, lunch in a container, etc).
My wife mainly uses the bag as a work purse, containing her wallet, cell phone, e-reader, jacket, sweater for work, and her lunch, and it still has plenty of room. She is constantly getting comments and questions about how it works and where she got the bag, and how it looks like "a big armadillo," which is, of course, the point behind the design.
The bag attaches at the top with a forked clasp on the carrier's spine side of the bag. I was concerned the clasp would rub against my wife's back and be uncomfortable, but the bag naturally sits off her back at that spot, so there is no irritation.
All in all I rate this item 4/5 stars for its design and use of recycled products. I subtracted one star for its size, and how it sits at the middle of the back, rendering the padded straps mostly unused.