My 4 sets of Formula Oros were all low or zero faff, one of them had a minor wear and tear part fail but then, they’re ancient, the rest were all just fit-and-go. Just took a set down from the box in the garage where they’ve been for 2 years, stuck them on the soda, and immediately working as well as anything else.
My Shimanos were slight faff, a caliper seal seized up and o’course couldn’t be bought seperately. OTOH swapping the caliper was cheap, and quicker than replacing seals etc so I suppose that’s still low faff but I wasn’t delighted to have to do it on a fairly new brake.