I've Tried Them All
I've used the HKS, Safariland, and Maxfire speedloaders in 5, 6, and 7-shot variations. Here's my two cents.
Maxfire -- cheap price, plastic rings with staggered height bullets that you load and twist into place. I did not like them at all. The twisting motion might stress the crane as well.
HKS -- solid and well-made, twist knob slows down the reload, but makes it very secure so that if you fumble the recharge, at least the loader remains intact.
Safariland -- Comp I (stub push), Comp II (larger rear stub), Comp III (springloaded, big suckers). I liked these the best. They are just push into slots and drop. A central cam presses against the cylinder star and releases the shells. Fast as all get-out!!
Speedstrips -- load 5 or 6 shells in a black rubber-plastic strip that you stick into 2 chambers of the cylinder at a time. Not especially quick, but better than fiddling with dump pouches or loose shells. Biggest upside is that they are FLAT and do not bulge at all, even in tennis shorts.