I purchased the Moxi WRKT skate backpack because it has storage space for a helmet, pads, etc. However, it took multiple positions and adjustments to finally figure out how to securely keep the skates in place without them sliding out. A diagram would be helpful. The quad skates carried in this skate backpack are a men's 11. They fit just fine and the weight distribution is good, it doesn't weigh you down.
I also purchased a Lil Popin Jo skate backpack. It's smaller, has less storage space than the Moxi WRKT and is comfortable with much easier packing and release than the Moxi WRKT. I use that backpack with a size 9 womens quad skates. However, though it says the Lil Popin Jo can accommodate inline skates, the size 9 inlines did not fit. I'd definitely use the Moxi WRKT to carry them instead.