I have two of them. The reason I bought it, and what I like about it, is that (1) it has D-rings to accommodate backpack straps, (2) it's lightweight but seems to be sturdy enough for traveling in the overhead compartment of an airplane, (3) it has room inside for a strap, a tuner, and some other stuff (the Crossrock shell case and especially its predecessor, the Kamoa shell case, had little room for anything other than the ukulele), and (4) it seems plush and fits well the ukuleles I use it for). I would prefer that it had clasps instead of a zipper, and it's a little bulky compared to the crossrock shell case (one of my ukes came with the crossrock shell case), but the plusses outweigh the minuses for my needs.
For the convenience of people who don't know what the CRA400 is, here's a link to its page on amazon.com.
http://www.amazon.com/Crossrock-CRA400TUGR-Hybrid-Ukulele-Case-Grey/dp/B00OIE0AT0/ref=sr_1_2?ie=UTF8&qid=1441141380&sr=8-2&keywords=crossrock