You won't be disappointed.
I have both, the G9 for about 3 months and have put over 13,000 shots through it, mainly in the dark rain forests of Costa Rica, the EM1v2 for only 3 weeks and about 3,000 shots. I wanted a 2nd body, so got the EM1v2 to try it and return if i didn't like it, but decided to keep it.
From my perspective the EM1v2 is better for BIF using CAF (always assumes I can actually keep the bird in the frame!) and the raw files seem cleaner and more natural than the G9.
I'm coming from a Canon 1DX2 and 500mm f4 so expect a lot, but both can produce good photos given good light, cropping at high iso's is a challenge, but not unexpected really. Again so far I think the EM1v2 is slightly better here, but time will tell.
I need to put more through the EM1v2 to come to a definitive answer but can see each has its advantages, more so if using the same make lens on the camera.
Regards,
Cliff.