It’s not even close to out yet, but the Pentax K-3 Mark III is notable for being the APS-C camera that you were waiting for – back in 2013. A newly-released presentation (below, via Pentax Rumors) goes through its improvements over the Mark II version. And there are some changes this time around, unlike the Mark II revision, where the name badge constituted the primary difference.
The pentaprism is improved with a corrective element. They have a faster processor, allowing them to apply ever more sharpening to images more quickly. The high ISO performance appears better by about a stop. The poor (for a crop sensor camera) 8.3 frames per second limit is fixed with an increase to 12 FPS.
Pentaxians are very sensitive about their controls, and ergonomics are everything to them. The firm lavished a great deal of attention to this, so that market may be happy with those results. That said, in the eight years since the K3 came out, the pace of progress suggests that Pentax – now a division of Ricoh – has been winding down its development efforts when it comes to sensors and the software that nowadays controls the major new features of digital cameras, such as subject recognition and tracking.