I bought the 10 litre one in what I consider to be a moment of madness. How much for a small rucsac, tube and bag!!!!
But a year on it has worked really well. There is a limit to the amount of spare clothing it will fit but its only an issue when carrying stuff for the kids
things I like (not necassirly unique but things I’ve used)
seperate phone type pocket at the top
rigid back means its never floppy
rigid bladder and handle means it easy to fill
bite valve has locked off position meaning no leaks
magnet to hold bite valve out the way
back pocket thing takes os map or d lock
pocket with key hook
it seems well made
will take a mountain morph pump
clever helmet holder (actually onlyused once)