Well...FWIW..I thought the Ruland couplings were mainly for high rotational speeds..aka to dampen vibrations coupling a pump to a motor..etc.
I noticed the new Losmandy adjustable worms have a Ruland type coupling...so they must be ok to use.
The oldham....I cannot really say apart that they used them for years, although many users had complaints about them.
But...that said.....these versions are vastly different to the old Losmandy types,so yeah...these coupling look ok.
I think the clamp might be better as it shrinks down the collar to fit the shaft...where are a set screw clamp clamps on to the shaft and could give more misalignment between both collar and shaft.
