I would go with the MSI M9,
I dont like EATX
That fact that the EVGA boards supports 4 way SLI on a Z170 board means they did some bandwidth trickery (PLX Chip) that in the end is good for nobody so that alone is a good reason not to buy it
MSI seems to have better on board sound.
MSI has wireless
The only negative for the MSI board is the Killer NIC which in truth will probably be fine once you get all the drivers loaded.
The MSI also has better fan program ability
Hey Thanks for your input,sounds like you know alot more than me lol.... looks like i will be going the MSI M9 than... i like how it looks too which is a plus.