Alright- That's helpful to hear. I've been debating hard about selling my 5D3 and getting the GH4 once the EF Speedbooster arrives. This hardware hack rumor has been getting in my head, though.
Of course, keeping both is an attractive option, too. I'm looking forward to shooting with the GH4 in a couple weeks and trying out some filtration to see what effect I can get with close ups on actors. I love the sharpness, but am worried about too much detail on close ups.
GH4 seems like one of the best nature-shooting cams I've seen. I'm about to start a project that's all nature footage and I can't imagine a better cam. 5D3 for timelapse of stars, GH4 for giant redwood and ocean vistas... Mmmmm....