I use Ortleib roller panniers for touring and Topeak DXP for commuting. I usually don't carry enough to fill a single pannier for commuting, and the Topeak is flexible in capacity, plus much less windage than a pannier. I like to ride fast commuting, and my route is usually windy. You can get a rain cover for the Topeak bag, whereas the Ortleib bags are waterproof. Either way is fine, but I really like the Topeak design. And as far as durability is concerned, I've been using both for years without any problems. The Topeak get more use than the Ortleibs, and it is holding up fine.
Last edited by alan s; 04-09-17 at 09:06 PM.