I use a variety of bags for different purposes, and own a lot more.
- Incase Ari Marcopoulos Signature bag. This is a very sturdy sling bag with a zippered opening, extra wide strap with quick release buckle, and was designed by Ari to hold a Canon 5D Mark II, Contax G2, Contax T3. When I'm working, the bag holds my Panasonic G9, assortment of Olympus primes and Panasonic zooms, or a couple of Sigma zooms, along with a couple of microphones, audio recorder, filters, batteries etc.
- Samsonite travel backpack - when I want to carry a bit more gear for work, the insert from the Hadley Pro fits perfectly in the Samsonite and carries my m43 kit along with my M9 and assorted lenses. It has hugely thick straps which makes it very comfortable, and it doesn't look like a camera bag.
- Lowepro Streamline 250 - this is a lightweight nylon shoulder bag with two padded front pockets for compact or mirrorless cameras and tiny lenses, an expandable main compartment for general storage, and an internal tablet pocket. I like this for when I'm only carrying a small camera and a couple of primes, but want extra storage space for snacks, drink bottle or a book.
- Crumpler Dry Red Boarding Bag - intended for travelers, I've lined the bottom of the bag with padded velcro inserts from my Hadley Pro. This bag fits a surprising amount, and I've put in my G9 with 12-35, M9 with Distagon 35 and a thick wallet. This is my walkaround bag for when I'm carrying either my M9 or a small mirrorless camera. Zip opening all the way, baby! Sadly discontinued, I should have bought a spare when they were on special.
- Alpaka Go Sling Pro - this is a new addition and I just love it. I have the limited edition x-pac fabric version and it is super light, holds a small mirrorless camera, spare prime lens, memory cards, batteries, filters and wallet. The strap has a quick release buckle and can be detached - I sometimes replace the strap with a Peak Design camera strap, which makes it even more comfortable. The GSP is designed with photographers in mind, and the zips are waterproof. I've walked with this in the rain and the insides stay dry, although I have sprayed it, and every other bag I own, with Nikwax Tech spray.
- Kata 3n1 medium - This bag carries my 5D Mark II kit, which includes the body, 70-200 f4 L, 24-105mm and 35L, along with batteries, filters etc. It's very workable for work and getting gear from A to B, but I'm not fond of walking around with it as it looks like a camera bag. In 2014, Kata merged with Manfrotto and Kata ceased to exist, but the same design team went to Manfrotto and many designs carried over. The closest would be the Manfrotto 3n1. Based on my Kata experience, I'd probably buy a Manfrotto if I wanted a larger camera backpack to carry a couple of bodies and large lenses.
I have many more bags, but those are the ones I use the most. Cote & Ciel bags are lovely but just not practical for me. Their straps tend to be too thin, the bags aren't shaped to hold objects like a mirrorless camera or rangefinder, and the zips are scratchy metal.
Billingham Hadley Pro - I don't use this much at all, as I have come to learn that I just don't like flap-opening messenger bags. I want a bag that I can unzip, pull out a camera, stash and zip up, and any kind of messenger style bag doesn't do that. I love the quality and looks of the Hadley Pro, but it just doesn't suit my style of carry and shooting. But I make use of all the internal padded insert parts.