There are as many bags, cases and backpacks as one can imagine.
Manufactures make items based on
materials
costs
colors
shapes
target audience
best selling camera kits
Tasks or specified uses (street, hiking, water shoots, studio, travel, lightweight carries etc.
I have been all over this topic for the last two years and have found many suitable solutions. I sent drawing to Wotancraft asking if they would make me a custom bag for my Leica M kit after several emails they told me they are trying to accommodate some of my requests in a future product and would keep me informed. NOT! Two years later they and Steve Huff gave an opportunity to provide your requests for a new bag that Wotancraft would produce. So I did and got a nice response once again from Wotancraft but after seeing the bag Wotancraft released it was a huge disappointment. Why because I want a bag that I can work out of. If I just needed a bag to sling on my shoulder and walk around with or to throw in a trunk I could use a Gym bag or a Tactical bag.
Backpacks
After buying five different ones FWIW get the one that's most comfortable on your back then worry about the pockets and inside they all work fine. I ordered a foam insert from a custom internet company tried using it not quite right, foam too thin and the depth of certain cut out are too deep. The company allows you to design your own holes but not the depth...now have Kasien foam on order and I'm going to make my own layout. The backpack is great for walking/ hiking to a spot with your gear, but presents some difficulties or awkwardness when you need to set it down and your on a mountain slope or at the beach near the water. I like working out of the backpack because its easy to carry and it also holds not only all my gear but a tripod, water, small portable chair, lightstand and umbrella so my hands are free. I have one for my Fuji system and one for my Hasselblad system. Also for just carrying a 15" macbook pro and intuos tablet with four hard drives and a camera with one or two lenses I use my Booq Graphite probably one of the best quality backpacks you'll ever buy. The bottom zippered compartment stores most DSLR's with a lens attached.
Bags
I have many and have seen some I'd love to try out. Not a fan of heavy bags if I was I'd buy the Holdfast Roamographer one small and one large bag. "Hands down the best looking camera bag." Also don't love stiff bags that take a year to break-in. A great bag needs to have side pockets that can hold somethings that are inside the bag that you pull out when your working. That to me would be lightmeter, filters, flash, spare battery (or dead ones), lens hood, lens or anything that you use temporarily or switch out...not sure why many bags manufactures don't grasp this concept.
I have always found that once I remove my camera and a lens from any bag the bag has plenty of ROOM but when fully packed its a usually tight fit.
The best solution I have come to is everything packs away in a backpack depending on the day and the shooting location. I either take the complete backpack or put what I want in a bag and leave the backpack in the trunk. This way I can lighten the load. I also want a bag the fits the camera body with a lens attached in such a way that I can grab the dang thing with one hand pull it out and use it without having to put the camera bag down to pull out the camera.
OH YA! I don't need to carry around a laptop all the time but one should have the option to fit one in the bag, why don't they make a bag that has a removable pouch for a laptop?
A great bag for the Hassey that I wanted to buy and in fact contacted ONA to see if they would make it in a different color for me but got a negative response: "ONA! We don't currently have any plans to produce the Astoria in another color, but I have put forward your idea to our design team for them to take on board for any future bags we produce. We typically announce new bags on Facebook"
The current Astoria if made in Black or a different two-tone color combination that didn't scream CAMERA BAG could work out nicely. Maybe Ill get over the FUGLY color scheme and buy one it wouldn't be the first time I bought a bag only to put it in a closet!!!