I'm honestly happy for those people that use their K-5 IIs and have nothing but joy with it. That's totally cool.
However, I'm not happy to let that count as proof that the "
threat of moire is greatly over exaggerated". If one of the reasons I list in my
"Pros and Cons of Omitting an AA-Filter" post applies, you won't get moiré. So, if one or more of the following applies, you are good:
- The spatial frequencies in the scene are too low.
- The lens is wide open and acts as a low-pass filter.
- The f-ratio is high enough to cause sufficient diffraction.
- The lens is slightly defocused.
- There is motion blur from camera shake or subject movement.
Hence, if you manage to establish one of the above all the time, you'll never have a moiré issue, even with a K-5 IIs. I suspect that camera shake is a frequent blur source that obviates the need for a Bayer-AA filter.
So for everyone who does not take painstaking precautions to get the absolutely sharpest image possible (which involves the use of tripods and/or flash) a filterless camera can be the better option. Therefore, paradoxically, the K-5 IIs is the better choice for people who take (slightly) blurry images to begin with, and that's completely fine.
I'm just opposed to the idea of the K-5 IIs being the best choice if you want to maximise image sharpness (because if you do, you'll have to deal with moiré sooner than with a K-5 II) and the notion of moiré just being a theoretical issue. The latter is clearly not true, if you get into the business of taking the sharpest images possible. There is a reason why manufactures spent the money on including Bayer-AA-filters.