rock_jock...
"I hate to belabor the point, but how is a moonclip faster than a speedloader?"
Simple. The moonclip is inserted in to the cylinder and remains there with the cartridges. You do not have to withdraw it as you do the speed loader, eliminating one or two extra motions.
And when you eject it (and the spent cartridges) they all come out as a unit, tending to eliminate or reduce the possibility of a sheel or two hanging up in the cylinder.
Think of a moonclip as a magazine for a revolver. Easy in, easy out.