Usually the reasons for swapping calipers is because the piston has tipped in the bore and this causes scoring of the bore, and piston and then it sticks. Other reasons are leaking seals, mostly from the tipped piston. Replacing the seals and cleaning the bore with a light hone is all you need to do to keep them working in great order. If it's not broke, don't fix it. change the pads when needed and watch the rotors for scoring or cracking. Keep the fluid up and bleed the system properly. Farthest wheel from the master first,( passenger rear, then drivers rear, then passenger, then drivers side).
Anyone who has extra money they don't know what to do with is encouraged to send it in a plain white envelope to me. I'll accept all donations.