How do KSF drybags fare regarding longivity (i have a ginormous 90L one)? I otherwise have some Exped ’olive drab’ (looks more like olive grey) ones (not the extra light), but these could be relegated to casual use should they be a problem, or used inside a larger bag.
I have since last century a pair of Ortlieb green PVC rear panniers which have lasted well, including surviving my occasionally falling off of my bicycle (one of my special skills): i have always put anything also inside a plastic bag or drybag, and have never had any water ingress into the panniers despite sometimes torrential rain—fun times when cycling.