Shot today with K3II and Tamron 17-50 2.8. I shot this a few weeks ago with a Canon 6D and 24-70 F4.0 L IS. I printed them both 12x18 and the k3II shot is miles ahead. I ordered a 16x48 and it's going to be interesting to compare that to the 6D one I got a few weeks ago.
Interesting to note what really struck me was the ease of shooting pixel shift/mirror up/IR remote. The Canon would give me fits using the IR remote and it didn't work with mirror lock up or some such nonsense. I know I was always scratching my head wondering what settings worked with what other settings. The Pentax just does what I want it to do without giving me any lip.
The AA filter on the 6D is very noticeable after shooting Pentax non AA cameras for the past few years. And pixel shift just leaves it in the dust FF or not.
Makes me wonder what the FF Pentax might be like WITH pixel shift... things are getting interesting.
Another thing about pixel shift, your lens only has to be 24mp sharp, not 50mp sharp, yet it gives you 45mp output. think about it.