For what it's worth, I Tend to remove mine once a year and clean and grease with Lithium grease, then replace. This at least ensures that when I do need to remove them, it's no great sweat. Usually takes me around 30 mins to remove, clean, grease and refit both bars, and therefore I can then just them remove in about 10 mins anytime I need to.
(I actually keep an allen key and spanner for them in the boot, just in case I ever need to remove them in an emergency)
As far as I am concerned, it's 30 mins well spent to keep things working freely.