The Grocery Pannier is No Longer Available as of 2015The Deuter Rack Pack Grocery Pannier excels for being just so easy get on and off the bike and for having a large volume. It uses just three hooks (two on top and one on the bottom) that are very fast to get on and off. These hooks then can attach to the front of your grocery cart. While "grocery" is in the name, we used it for just about everything from commuting to work to delivering packages. Most other panniers we have tested are not nearly as easy to get on and off. As a result, we find we end up using the Deuter system the most.
The main downside is the upper structure is flimsy. When fully loaded, it moves around, pokes out and is a un-gainly. There are no compression straps to bring the load in closer to the bike so items can shift and hang out. In some sense, it is the tradeoff for the bag being light and compressible, however, it there was just two small compression straps on top that ran perpendicular to the bike, this issue would like to be resolved. In the meantime, you can address this issue by adding your own compression straps and bungee cords. We bought bungee cords and were happy.