Hello, Richard nice site! Nice poll! One suggestion to make it IMO a bit more accurate. No one disputes the DA*300mm, DA*200mm or DA*60-250mm are for the most problem free. The main complaints are toward the DA*50-135mm and DA*16-50mm. I would aggregate all of those lens for you percentage as this will more accurately reflect what we already know, and what we don't know; or in other words get your figure closer to the actual failure rate of those two lens.

Also if you consider any QC problem, SDM or not, say slow AF, as we are not able to separate issues with the facts we have that may have a root cause in the SDM system, or at least for the owner it does not matter as it may still be poor QC there is no way to separate the two. the percentage of DA*16-50mm and DA*50-135mm no matter how you want to add it, on your own poll, is kinda high. I won't say the exact figures as this is your show and I may have added wrong, I for sure am not perfect at 2:00am. Just my two cents