I ride with panniers now, just a fresh convert. I don't always have much in them, sometimes just a pump, flat-kit and mutli-tool. I don't really notice the weight when they are full, and I usually do 5-10km trips without any issues, and I have them mounted on a bike with pretty aggressive geometry, they are just far back on the panniers and my size 12 feet don't hit them. They aren't anything special or fancy but they get the job done. I used to have a small shoulder bag, and it's much nicer to have an exposed back. I also only have one pannier and it's on the right-hand side of the bike. I hardly know it's there. I find riding with a knapsack with a similar load to be much more uncomfortable.