If you want to film, get the GF5, if you want better images, get the NEX
I shoot mma, currently with a GH2 and find it very often limiting in low light compared to my Nex 5 (sony nex 3 is the same, just no full hd video). Don't have much problems with the autofocus at all on the nex. Image stabilization is so much better too on the nex, achieves me to take pictures where I wouldn't be able to with the GH2.
MFT has much better video though.