The ultrasonic cleaner is very effective for drivetrain parts. A friend of mine has one and cleans his chain/cassette with it on a regular basis. It gets VERY clean. He also gets 5K-6K from his drivetrain (runs Shimano DA stuff).

But, alas, he doesn't ride very much, and isn't very fast, having spent most of his time being anal with cleaning. I would rather be fast than have a spotless drivetrain. To do both of those is too time-consuming.

I have also had very much the same experiences as cast-iron with lifespan, it does vary considerably between components.

Recommendations, however, are much better taken when specific examples are given, instead of harsh criticism. I believe this to be an extension of the "elitist roadie" attitude which is displayed so prominently, where everyone has the best answer. I certainly don't claim to know it all, thats for sure.

Cheers~