I bought a Kata 3N1-35 PL to replace my LowePro Fastpack 350 camera backpack.
A few key points
1) The padding of the LowePro around the arms and back is much softer and thicker compared to the Kata bag
2) Inside space is about the same actually although the upper storage space in the LowePro is much larger. The lower camera storage space might be slightly larger on the Kata. It does seem deeper.
3) Inside padding is about the same on both bags.
4) Access to the inside of the bag is better in the Kata with openings on both sides
5) The Kata offers many more configurations for shoulder straps
6) Kata comes with a tripod mount. This is a big plus.
7) Kata comes with a rain cover
The last few points are the main reason why I bought the Kata bag. Overall I bet I use both bags at different times.
The LowePro comes with a nice little internal zipper bag as well as memory card slots.
Which bag is better? Very hard to say. I lean slightly toward the LowePro but they both have pro’s and cons overall.