I own the KATA 3N1-33 bag, which I bought mainly for travel. Last year, it cost me about $140, and it seems like you can have it for $115 in the US now. The main advantage I see for this model over the other two KATA bags you mentioned is the top compartment that lets me carry some non-photo stuff that may be needed as a carry-on (you know, underwear/toothbrush for 1-2 days, until lost baggage is found). It fits conveniently in the top compartment above the airplane seat, and holds a nice amount of gear (can get heavy when fully loaded, especially with a big laptop). Its ability to open on the side to get your camera out w/o opening the main flap is great, and I use it a lot. It also doubles as a sling bag configuration, but I never use it in this configuration.

Its build quality is great and it keeps its form and shape after a long time of use.

On the bad side - the lack of chest strap is annoying, especially when it is fully loaded. However, you can use it in the 'X' configuration to overcome this. The access to the top items in the main compartment is a little hard b/c the main flap opens from bottom up. This also made me drop two lenses when forgetting to close the zipper (...)

The Owl looks like a smaller version of the 3N1, and seems like your space for non-photo stuff is more limited. I must admit that I can't see why this bag is significantly costlier than the 3N1.

For comparison, I also own the Norazza Ape Case 2000 PRO bag. I used it for a very short time and then got the KATA. The main reason is it being so-big. Although when measured it is not much bigger, but it is certainly much deeper. This made it inconvenient for me. As for build quality, the Ape looks sturdy, but it can't compete with the looks and feel of the KATA. The KATA is much more elegant. I guess this is why KATA's cost more.