Originally posted by Eulogy If you're implying a motor design issue, it's invalid, and 90% of copies are still working fine. 10% failure was just too large for "Acceptable rate of failure" to cover. Look for Canon USM failure rates, they're probably around 1-3%.
You actually don't have exact numbers. Unless Pentax releases the official numbers, which would open them to consumer action in at the least Europe for pretty much all they are worth out here, you're using numbers that aren't grounded in realiity. There's a register, sure, but it's not going to encompass the majority of buyers, unless you believe the majority of buyers are on this and other pentax forums?
The international forums aren't so nice about the SDM failures, particularly the French and German ones, but the EU actually has strong consumer protection laws that Pentax has been trying to not get involved with. People on the German forums are reporting their fourth repairs in their megathreads. Each repair is about 300 Euros and the supposedly new parts are used and they are still failing in six months to a year, with Pentax not honoring repair warranties.
I don't know what you're reaching for, but even Pentax has said, which I'm sure resulted in a reprimand, that there is a design issue. What is implied, directly from that person is even if the parts were redesigned, no amount of improvements to them will make up for the design problems. Also, ever year we hear they've fixed the problems and the same issue every year- the lenses are failing in high numbers.