Originally Posted by
marmot
The thick, rubbery dry bags don't weigh much less than comparably sized panniers. When you factor in ease of use and convenience of access, I'd stick with panniers.
You don't need thick rubbery dry bags. I have Sea to Summit bags and they are waterproof and very very lightweight. I still prefer my thick Ortlieb Roller classics though. For long term they will wear better, but I do strap on a Sea to Summit dry bag or two when I tour. I could sse them working but I doubt they would last as long as the Ortliebs.