I have the topeak dynapack, but only for the last few weeks so can't give a comprehensive review- few first thoughts: it's not water proof- even with the cover over the top, you can hardly notice it's there- going over speedhumps is the only time it makes a noise and you never feel its presence, good capacity as I use it for work, uses up a lot of room on the seat post- means it's tricky to get a smaller saddle bag on for pleasure rides (unless you have two bikes in which case ignore it). Takes clip on rear light onto the reflective strip at the rear but not sure how well this will work when I have the cover on. Otherwise it's a good piece of kit- bought to replace my rucksack when my commute distance increased- recommend it (so far)