I have a client who would like a hinged ring and so far it seems
there are a lot of negative reviews of Superfits, saying they fail
after a few months.
IMO the superfit shank is the best adjustable shank ever devised. All
adjustable shanks fail after a certain time, that's dependant on how
the owner treats them and how they use them and how often they take
off the ring. I've seen superfits that were some years old and had
some play to them, but were still going strong. FWIW