Originally posted by Fluegel I am sorry to read about the bad luck users of more recent bodies have.
Forums and sites that offer cameras for sale warned me about these issues.
It's worth bearing in mind that the aperture control solenoid issue that effected the K-30 and K-50, and to a much lesser extent the K-S1 and K-S2, has been addressed. The mechanism in the later K-70 is modified (as noted by our forum member @photogem). And none of the high-end bodies - K-7, K-5, K-5II, K-5IIs, K-3, K-3II, KP, K-1 - were affected, since they employ a different method of controlling the lens aperture. So, whilst I think it's fair to say that
some users experienced problems with certain cameras manufactured
several years ago, higher end and current generation cameras are absolutely fine. Don't let the problems with the K-30 and K-50 colour your views on all recent bodies, because Ricoh / Pentax has learned from this and moved forward.
Originally posted by Fluegel One of my caracter flaws is a poor ability to cope with defective gear.
None of us is overjoyed when our equipment fails.
As I'm sure you know, there are camera models from
all manufacturers that have had problems, and it's hardly surprising, since these are increasingly complex devices. Even models that have proven to be extremely reliable and largely problem free can still fail. Look online for long enough, and you'll find reports of failure for pretty much every camera from every manufacturer.
The best you can do when choosing a camera is to research it (as you've done), avoid those models that seem to have a particularly high failure rate in normal use cases, then either buy new equipment with the longest possible warranty, used equipment that has been well looked after, or inexpensive used equipment such that failure is of minimal financial importance.
Your K20D is a fine camera and will likely remain problem-free. But if you should ever decide you want a more recent body, there's really no need to worry. Simply choose one of the higher end models - K-7, KP, K-5 / K-3 / K-1 series - and you'll do just fine. Even the K-70 should be a pretty safe choice, since - as I mentioned above - the aperture control mechanism has evolved...