Over the decades I have carried gear in just about everything. It depends what you need it for. Commercial stuff, with Hasselblads, Nikon's etc I used the Domke New Yorker from 1975. It could hold most everything you needed and you only had to hand it to a client and they would OK money for a "schlepper" to carry it! Easily topped 40-45 pounds.
For my rangefinders I use a Brady fishing bag, the Ariel Trout. It comes with a plastized insert (thus you can fill it with water and carry the live trout home! I usually remove this and use one or two towels as padding (one is folded at the bottom and the other is stuffed between bodies).
They have to front pockets that will hold my pipe, a can of tobacco and some matches and the other one holds odds and ends like folding knife, spare keys and all that stuff you think you will need, but rarely do,
No velcro anywhere, leather straps with brass "fittings" and a webbed. wide strap. The advantage is that it looks like a book bag (and will hold a regular sized magazine 8.5x11). The canvas "duck" material is virtually impossible to wear out (2-3 years).
I can fit 2 M sized bodies with lenses, an extra lens and some doodads in it. For traveling, it is small enough and inconnous enough not to attract attention. They are bit tricky to find and I usually buy 3 at a time (7-8 years supply). I have used them for the last 20-25 years and not found anything that is better.
