I Have always used HKS speed loaders, I have several of them for M36 M10 M547 & recently aquired three Safariland Comp IIs for my M547.
After using the Comp IIs I'll have to say that the Safarilands are easier to speedload with but are a bit harder to load, but with practice they can be loaded without too much trouble.
The Model 547 speed loaders have been discontinued & I was lucky to score them in either the HKS or Safariland, Thanks to the Forum Members here who hooked me up!
Now To Score 3-4 for the 586/686..
Gary/Hk