I see by the number and speed of responses that the search for "the" bag never ceases to be of interest! I have a slew of them, and I'm constantly trying to figure out how to apportion my kit among them in the optimal way. It takes a while to learn what you really need in a bag; and by then you've accumulated an entire luggage shop's worth of bags that seemed like a good idea at a time.

Herewith, as best I can recall, for the amusement and mockery of my fellows here, my current bag inventory, accumulated over decades of buying and selling camera gear, and occasionally actually using said gear to make pictures:

1. LowePro Commercial AW MF: bought for Contax system, now holds Lumedyne lighting kit;
2. Pelican PCS104 rolling bag: huge beast, bought for studio strobes, stands, etc; sitting unused, just too damn big and cumbersome;
3. Lowepro MiniTrekker: bought for D70 outfit, now empty;
4. Lightware 1623: bought for ?whoKnowsWhat?, now holds Dyna-Lite gear;
5. Ginormous Halliburton case: can't remember what I bought it for eons ago, empty;
6. Small Halliburton case: came with Sinar gear bought 20 yrs ago, empty;
7. Domke F-1x: bought as "day bag" to work out of; houses Mamiya TLR stuff;
8. Domke F-6: bought for, and houses, Mamiya 7 system;
9. Think Tank Photo Airport International v.2: bought for, houses D300 kit
10. Pelican 1600 with dividers, non-rolling: bought for Contax kit and younger man's back; houses little used parts of said kit;
11. Pelican 1500 plus dividers, non-rolling: came with Contax kit, was outgrown; houses trimmed-down Contax "travel" kit;
12. Ancient Tamrac shoulder bag, about Domke F2 size, bought for Nikon F3 kit 20 yrs ago, holds filters and small gewgaws;
13. TTP belt pouch system: used for variety of systems when bag makes no sense

My wife mocks me relentlessly; I retort that, were I a golfer as she is, this number of bags would be as nothing.

My current operating principles re bags are that they must be lightweight and ride comfortably on shoulder or back; or, failing the lightweight part, must ROLL. It is also nice if they can be carried onto a commercial aircraft, should I bestir myself to travel. That winnows about half the above inventory, bought during less enlightened phases of life.

I am really liking the idea of the photobackpacker component cases---they could easily be configured into a Pelican rolling shell without that hideous foam or the more-useful divider set; that would preserve the option to add a backpack later if it becomes necessary. Heck, I could even maybe rehab one of my ancient Halliburtons for the purpose. Schwing!

I would never have imagined the Chamonix might fit into a small LowePro backpack, and since I have one unused, I'm going to give it a go. Great suggestion. As for the much larger PhotoTrekker: I once tried this one from a friend; it is a bruiser whose main virtue is accessibility of contents, so good for working out of a car; but very heavy, and too large to carry on an aircraft For a backpack that I'm actually going to put on my back, I'd just as soon go with the lighter (?) and more comfortable Kelty from photobackpacker.

Ditto the Domkes. Never thought of that, so I'll try it with one of mine. I really love those Domkes; great to work from, easy to carry.

Thanks all. More suggestions welcome.