i have a pair of sidi's first 'srs' mtb shoes from 2000. i thought that was just what sidi's needed, a replaceable sole. but i came to realize that a sole that's as minuscule as sidi's are, simply doesn't perform. they have no traction in wet conditions, they're loud on hard flooring, and i find it far too easy to roll your heel. so the fact one can replace them is...irrelevant.
but now we have the sidi 'outdoor' sole, on a shoe with ye olde shoelaces. sure i like the micro ratcheting buckles, but it's a mechanism with moving parts that can fail. then you order another, you wait...in the meantime you're a cyclist without functioning footwear. if your laces fail, you get another lace, or paracord, or whatever is laying around, and then you ride...then and there.
and the sole is a true , full sized proper sole. i did remove the velcro strap. i cannot stand velcro. because it fails. cycling footwear needs to be tight, secure. given time, velcro cannot provide tight security. the velcro strap on this shoe is there for reasons i cant surmise. so i removed them, voila! a true shoe!