for handheld video and long lens shooting, GH3 or EM5?

Just received my GH3 this week, alongside the 14-140 superzoom. I planned to use it as a video camera : A majority of the usage would be indoor, chasing babies and young kids. Though there will be a lot of day time walks, theme parks and vacation trips to follow.

1) Video:

I've tried the Sony CX760 and to be honest the OIS on that thing is insane. You can walk around and shoot pretty steady 1080/60p video. The 26-260mm equiv f/1.8-3.5 Zeiss lens is not slouch either. But the price tag is high, and you can't change lenses. The GH3 isn't all much behind, shooting 28Mbps 1080/60p. At 50Mbps mode the GH3 videos are less noisy and a lot cleaner.

The GH3, in comparison is not as steady when you shoot video walking around. I am not sure if switching to 12-35 f/2.8 or 14-42X would get any better.

Having read about the EM5's IBIS I begin to wonder if the EM5 is actually a better walk around video machine. Even with the Panny 12-35/2.8 mounted it is still fairly small.

The only downside is EM5 does not shoot 1080/60p. I'm rather used to shoot 60p even for everyday video clips as it is so much more smooth and fluid over 1080/30p or 24p. That said I mostly shoot consumer grade baby/kid/vacation videos, so I am not sure if the GH3 is a bit of an overkill.

2) Long lens shooting:

I shoot the Nikon D800E for stills, and the lenses are all huge and heavy. The Panny 100-300 is a huge attraction to me, and nothing like that exist in the DSLR land. I plan to mount a 100-300 on either camera as a lighter birding/wildlife alternative.

I've tried the 100-300 once on the GH2 and was hugely impressed. I believe the 100-300 type of long lenses is the very type of application that m4/3 can do better and lighter than DSLRs.

The 9fps on the EM5 does tilt the balance to its favor. I was not impressed by the frame rate on the GH3 for continuous shooting.

For what I plan to do with both cameras...which one would be a better fit? GH3 or EM5?

Many Thanks,

PatrickP