I first found out about these things about 20 years ago when they were a fixture on many randonneuring bikes. I finally got one and not only am I really impressed with how well it stabilizes the saddlebag, I also really like the niftiness of being able to take it on and off when I go into a store. The quick release mechanism is somewhat janky, but with a combination of repetition, muscle memory, and a moment of committed piercing concentration the bag comes on and off consistently and smoothly. It works, but it needs work, and you should take pride in the new small skill you’ve mastered. With my bag I can hold a big honking chain lock, several “nutritional” food bars, a liter of water, a tube, a pump, tire levers, patch kit, multi tool and ancillary wrenches, and small bottle of lube, all held in place with a rain jacket. Undergirding all of this is the Bagman Support, which works to keep the bag stable and supported. I went to the park and rode down a set of four concrete steps carrying my usual load about 10 times, just to test it. It’s fine, although I do anticipate a periodic bolt retightening here and there, probably with a fresh application of locktite. I’m getting ready to do 450miles off-road with it and that will be the real test. My concern there, yet unverified, is that the metal hoop will snag on branches and brambles during sections of excoriating hike-a-bike, or that even a small crash will render the Bagman unsightly or, worse, unusable. We shall see.