Just saw that my favorite nature shooter, Kevin Railsback, has posted a blog entry about shooting on the HPX250, and a video of what he got. Stunning work, as always.
http://filmmakingnaturally.com/an-iowa-morning-testing-the-panasonic-ag-hpx250/
Stunning imagery. As far as Im concerned the camera is probably the least part of the equation. What I loved was the light and shade captured in every shot - excellent composition. Amazing.