As you know, I like much about the appearance of my gold/brown K-r. Practically, it is a nice camera and good piece of photographic tool putting aside the persistent front focusing issue under tungsten and the last isolated accident that I have encountered.
However, I am so annoyed with the tungsten FF issue as I do shoot indoor with my fast Pentax primes from time to time. Indeed, the problem is most troublesome when there is mixed white and yellow light sources, under which there is not a single "fine focus adjustment" factor that I can safely enter to avoid the AF errors. Otherwise, for indoor environment that is with tungsten source only, I could quite safely to use a -10 adjustment factor to compensate for the error that must occur with the K-r in that case.
Just with this problem alone, I am now seriously considering to move to a K-5, which has a SAFOX + (Plus) AF system, which theoretically should avoid the problem. However, for what I have made my research so far, it seems that there are still some K-5 users, who have already upgraded to the latest K-5 firmware of version 1.03, do yet encounter some AF problems, although it seems that it is not as severe as the K-r's. See this example.
So, after all, I would need to seek assistance from all you folks who have used your K-5 for quite a while, and most importantly have been shooting under tungsten or mixed light sources indoor wider opened with faster lenses, to give me some advice about the AF reliability for this application. Your information provided will surely help me to make a better decision and to help me to re-configure my Pentax gear with a better setup/lineup.
Thank you in advance for all your kind help and inputs. Here we go!