Originally posted by biz-engineer no, the reason why the 645z get the same AF module as the K-3 is because MF is not targeted at sport and wildlife applications, therefore even if the AF is grouped in the middle of the MF frame , it's not an issue.
However, FF is having higher iso perf and still very much used for sports, which is why it makes sense to upgrade the af module on the ff camera. If Pentax uses the K-3 AF module on the FF, it's going to be a big minus for the camera, but I think there is a very high chance that Ricoh redesigned the AF module for the FF , with potentially reusing this more advanced AF into a future APSC camera, like Canon and Nikon are doing: you just get a larger frame coverage on APSC.
I'm pretty sure that the ff camera will be good to cover most people actual needs (K-3 is already such as camera), but once again, people (and also Ricoh) focus more on camera only then on lenses. That's not how to evaluate the capabilities of a camera + lenses system. Right away, if it has a full frame sensor inside, you'll immediately get less noise and more overall resolution versus APSC (I remember the times of the so good DA limited primes APSC of Pentax... that are actually wiped out by any full frame system even with an average lens on it...).
Is there any DMF camera targeted at sport and wildlife applications?
As I said, the 645z can meet and exceed it's expected performance by reusing K-3's AF - they didn't had to develop an entirely new AF system. It's a highly competitive product.
OTOH sports is the wrong application for the format. There you need speed, not exquisite image quality.
The K-1, OTOH, while not being targeted at sport itself, must be competitive in its group.
As for focusing more on camera only, hmm, let's see:
Cameras: K-1
New lenses (we know of): 150-450, 24-70, 70-200, 15-30, 28-105