Originally posted by landscaped1 The SDM is what is holding me back.
If you have doubt about IQ, or ergonomics, or usability, trying it out for a week or so makes sense, but that won't address your concern re. SDM failure. There is little chance that the SDM fails during the time you have the lens.
If you buy it now, and pay with a gold/platinum VISA/MC, you'll have 1 year warranty from Pentax, and additional 1 year from the credit card company. If the SDM fails, it's likely to fail within the warranty period.
I say just buy it.