I've had no issues with the Topeak clip one (a medium).
Had to buy the alternate F22 brackets to get it to fit on the Brooks saddles.
Holds 2 tubes, biggish multitool, Park tyre levers, PRK & tyre boot, spare nuts, bolts & chain link, thin rubber gloves to keep hands clean. Good strap on the back for attaching Smart 1/2W. Never use with expander zip open. If I need more luggage space (clothing/food for longer rides) then the bar bag goes on.
I have a
Decathlon bottle tool holder as an alternative to the wedge bag, but struggle to fit it all in, even cutting down to 1 tube. It only gets used on particularly hilly rides, when I want to take off the Topeak bag and bracket, so as to get the saddle a bit further forward.