K70 possible aperture motor control problem looming

I was looking on line for pricing a K70 and saw a refurbished one on the Wex site. It had been sent for repair for underexposing; the shutter mechanism and mirror mechanism were repaired. I hope this is not the K30/50 problem here.

There have been a few reports of the same issue. If the mechanism is built differently to the K-30/50 one then this shows it still isn't as durable as the one that is found in the flagship bodies.