I have an Altura, probably of a similar vintage to Frank, and a Bike Bureau, while they are both good the Carradice wins out hands down if I was to go to a single bag, here's why.
- The Altura is not as waterproof, has a plastic condom thing to make it more so. If I know I'm riding through a downpour and need to carry the laptop, it will be in the BB
- It is smaller, using it for clothes and laptop is not as practical. Clothes, laptop and shoes is stretching it
- it doesn't wear as well, so I tend to leave it at the office when I can, which gives me more flexibility and has kept it alive. The zip to cover over the pannier hooks went years ago, but no big deal