Oh you had to go and open that can of worms... <sigh> I have a lot of bags.
Well... I have:
Tenba Universal Roller
Roadie Universal ? Black | 638-327 which I bought to replace my
Tenba Shootout Roller Backpack (Medium)
Shootout Rolling Backpack LE Medium ? Black | 632-345 (which I still have but don't use anymore. Doc won't let me use a "backpack" anymore.)
I also have quite a few ThinkTank components.
ThinkTank Digital Holster 20 v2.0
Digital Holster 20 V2.0
ThinkTank Digital Holster 40 v2.0
Digital Holster 40 V2.0 (same as 20 but designed to hold a "gripped" camera)
A couple of ThinkTank belts (one of which has a vest-type tech harness to help hold the belt and other accessories) including:
ThinkTank Lens Changer 75 Pop Down
ThinkTank Lens Changer 35
ThinkTank Lens Changer 15
ThinkTank Lightning Fast
ThinkTank Speed Changer
THEN I've got
Lowepro Toploader Pro 75 AW
I've got a Lowepro lens case designed for a 70-200mm f/2.8 lens -- but Lowepro doesn't really stick a name on this so I couldn't tell you the model.
I've ALSO got a
Kata Select-18 UL (they don't seem to make this bag anymore.)
And I still have a few other bags that I didn't bother to mention because those don't get used anymore.
The bags I use the most are the Tenba Universal Roller which I bought for airline travel. Very roomy - about the size of a rolling luggage and sized to fit in the overhead bin. My Shootout backpack was a bit "thick" and sometimes didn't want to fit in the bin unless I took a few items out. But much of it's thickness was due to a laptop compartment and a compartment which holds all the straps and harnesses for when you decide to wear it like a backpack rather than roll it. My lumbar spine is degraded so my doc doesn't want me wearing this kind of gear on my back anymore -- so that bag was retired (but I really did like it.)
I use the ThinkTank modular system ALL THE TIME. I love that I can just grab the modular case for whatever gear I need at the time and leave the rest at home (or in the car if I'm on the road.) Now I have my camera and *just* the spare lens or lenses that I need at the time and it's worn as a belt -- not over the shoulder or in a backpack. Easy to access and not in the way.
The LowePro Toploader and Kata Select bag just see occasional use. These basically hold the camera and I can modularly attach the Lowepro lens bag to the Toploader bag so I have the camera and one spare lens only (sometimes I drop the flash in there). The gripped camera fits extremely well in this bag (better than my other holster bags) but also this bag comes with an extra strap (in addition to the shoulder strap). The extra strap goes around your waist like a belt and holds the holster to your side. It keeps the bag from banging around if I'm hiking and also keeps it close to me if I'm in a crowded environment (e.g. concert events). When I don't need the extra strap I bunch it up and shove it in one of the mesh pockets on the side.
The Kata is similar but the fit isn't as good -- but the compartments that hold a spare lens or flash are zipped into the sides of the bag. You unzip them and they flip out to create pockets. I thought that was _really_ handy to just be able to add a pocket large enough to hold a lens or speedlite without needing an extra accessory... but I hate the "fit" of how the camera just plops on the inside. Nothing really holds the camera in any kind of position (perhaps this is why they discontinued it).