How difficult/easy is it to take the panniers off? I used to use on, but it was a pain to get it on and off (some clips to hang it but didn't lock, 3-4 velcro straps up top and one elastic loop at the bottom made it enough of a pain that I switched to using a folding wire basket instead. I'm tired of those and looking to go back to removable panniers if they're easier on and off than what I have now.