I have a similar rack but didn't like it after trying a few times. It is higher than a regular rack, so with a truck bag the weight is centered much higher and affects handling. A much better option is to use a large seatbag such as the Carradice Barley or Pendle, or the Acorn large bag. All of those bags hold just as much (or more) gear than a typical trunk bag, but they center the weight much better so they have little affect on handling. Carradice and other sources (such as Velo-orange.com and Rivendell) sell special racks that support large seat bags, which is needed with some frames. Here's a photo of my Barley and the seat rack.