Oh come one, what's with you guys. APS-c uses every one of the K-mount lenses ever made, FF cameras won't use many DA lenses.
A 36 mp camera in crop mode is 16 MP. A k-3 is still 24 MP packed into the area of the crop sensor. More magnification. Once pixels are captured, there's no difference whatever size crop they came from.
A superior product... only for those who didn't buy what they needed the first time out. For those of us who bought into APS-c because of the strengths of APS-c, and FF doesn't change anything.
You guys and your Full Frame wet dreams, keep it real. if you can't make a case without the non-sense, you really don't have a case do you?
As for lenses over matching sensors. Absolute non-sense. My DA*60-250 with a 1.7 converter is still razor sharp. The K-3 sensor can handle 1.5 magnificstion, which means you can got to 50 MP in a DA* and gain resolution all the way. Maybe some of your cheaper glass will drop off. My consumer A-400 doesn't do as well with a TC, so maybe some lenses can't handle a 50 MP sensor, but I'm sure any DA* can.
I know you think you sound smart, but all I really here you guys saying here is "We don't really have enough experience with Pentax gear to understand the strengths and limitations."
Well anyway, 'nuf said, feel free to wander back into Full Frame la, la land.
If you can't get narrow enough DoF with an APS-c, FF will save a few shots for you.
If you need more resolution than what you have in APS-c for landscape MF is the ticket, but FF is the a good compromise, if you're willing to compromise.
If you want maximum resolution in the are of the crop sensor, APS-c is the way to go.
You can make a case for FF without trying to get folks to look at the world through your reality distortion field.