My wife and I are riding a pair of Trek Multitrack 7000 bikes. Long rides on rail trail with shopping in cities we go through.
Each of our bikes have the Topeak Explorer tubular racks, without the springs. Our bikes have linear pull brakes, not disks.
Our bags are the MTX Trunk bags.
Our first set of the Topeak MTX bags did not last very long. Sewn seams started to come apart. Especially around the bag top zippers.
I bought another larger set and took a close look at the seam sowing before putting my money on the LBS counter. These bags have now been in use for 4 years. Used between 70 and 90 days a year. Carried all sorts of things in the pannier bags.