I have owned several Billinghams bags, 550, 225, extra pockets etc. but my current favourite is the L2 (discontinued). It is a size that can be carried all day yet will accommodate much more than you might expect looking at its size. Mine usually has my 5DsR with 16-35f4L (or 24-70) lens, spare battery and filters, pens and notebook, penknife, sandwiches and chocolate in, but sometimes it has water, a down gilet and a book or sandwiches in. Yet it is so small and unobtrusive. I love that it has brass feet and is reinforced with extra leather to keep it rigid. The only thing that could improve it would be a document pocket on the back (zip placed where it can't rub please!) :) No one else makes bags of this quality and style The nearest now is the S3 but it doesn't have brass feet which to me are a must for me :(