So the IRD and Sunrace FWs wear quickly, is that what you're saying?

I've used a few of the newer Shimano 14-28 6-spds. I have only two issues with them, neither terrible. The sprockets do seem to rust quickly if ridden in the rain. The bearing races seem to be not as even as they ought to be. The result can be a click on every revolution as the wheel rotates under pedal force. While freewheeling you jsut hear whatever soft wheezing it makes anyway. Hesitate just a bit on the pedaling to let the inner and outer sections be in a different relative position and the click may stop. It's not a problem because the bearings aren't rolling when it's under pressure and there is no pressure when they are rolling. Just a bit annoying.