I fly the gh3, and for video, I have no desire to switch to my canon dslr's, even though I am much more invested in canon glass. The added benefit of light weight seals the deal.
I still favor canon DSLRs, ill take the small drop in flight time to the added benefit of better glass and camera options. Also the heavier camera can help dampen any small vibrations a smaller camera will pick up
I've used the Mark III, T3i, and now the GH3. I LOVE the gh3 for a few primary reasons: its lightweight, 1080 60p, and if need be, an intervalometer for stills without the use of my Strattosnapper2.