Originally posted by Aristophanes love it!
I started with a Kata bag, which is useful when flying as I can use the trolley insert to stick it on top of my main carryon (usually travel BA who are pretty lenient on carry on), but when I am out and about I use a Berghaus 45 litre rucksack with a good adjustable freeflow back system. It also has a chest strap which the kata doesn't which makes it more comfortable on longer trips ( I often walk more than 15 miles on good days so found the kata quite uncomfortable and sweaty on a long day. The Berghaus also comes with a built in cover to keep rain out