As much as I love my K3 and 645D for stills (landscapes, nature), I bit the bullet and bought a GH4, a 14-42 mm kit lens and an Olympus (Panasonic compatible) 9-18mm WA lens, along with a K3 to m4/3 lens adapter.
What numerous other reviewers and sites have said about the GH4 video is true. It's in another league with IQ and flexibility beyond anything Pentax, Nikon or Canon offer in a DSLR or mirror-less design. The 4K video down converted to 1080P is a knockout, looking far better than anything I've ever coaxed out my previous Canon 5D2 or my Pentaxes. And FWIW, the Camera Store in Canada just did a AF comparison test and it's obvious the GH4 is far ahead of Pentax in this area, as well. Oh well.
GH4 Video Primer