I would think I need to know your photography behaviors and habits, like what do you shoot, where, how long do you carry your bag for, how do you want to access your gears, how often do you change lens etc.
For example, my needs are specific. I do street and hiking, so I walk a lot with my gears, but I also change lens very frequently, so side accessibility is crucial. I don't want the bag to be too bulky, but want extra space for a bottle of water amongst other accessories blah blah.
For me, I started with a regular "box" shaped shoulder bag. It holds everything I have and super easy access, but it puts way too much pressure on my shoulder.
Then I got a Lowepro backpack that holds way more than what I have plus a laptop. Then I realized that it's way too big and it doesn't make sense to carry laptop with it, just way too heavy. I only do this when I am flying and don't want to check my laptop and camera in to the luggage.
Then at a photography gear exhibition, I finally had the chance to see Kata bags in person and I bought 3N1-22. It's the perfect size for me with side access. The straps can also be converted from double to single, making it very versatile depending on how I need to access my gears. The compartment is just enough for what I need, and comes with a small rear compartment that I can use for water bag (it's meant for small laptops). I am very happy with the bag so far, too it on some long trips already. Solidly built, quality construction.
There is a latest version of the same bag. Same size, same compartment design, but way more expensive. The 3N1-22 is the previous gen product so they are marking down the price. I think the only difference is the color and material finish, as well as a new metal external spine to protect the bag from impact. The 3N1-22 also have such protection mechanism, but using a different material. I just thought the price difference is too big, so I went for the older version which looks great.