I have decided against using the soft claws. During my trial, on 5 cats, this is what I learned:
LIKES:
they can't harm funiture
they can't scratch me
they do look cute

DISLIKES:
the cats HATE when I need to push them onto the nail! (I do not want them to become fearful of nail clipping)
they come off sporatically, so I am ALWAYS in need of replacing one
out of 5 cats tried, only 2 kept them for more than 3 weeks.

BUT MY #1 COMPLAINT IS:
as the caps start to move away from the cuticle, but before they fall off, there is a gap between the cap and the cat's nail that forms a ridge. Jim got a strong string looped over that ridge and could not get loose. The string was one that could not be broken and was connected to a heavy object that could not be moved by a cat. The ridge formed by the nail cap prevented the string from slipping off the nail. If I was not there to cut the string, I can only imagine how much damage may have been done to his little foot.