What will happen after upgrading to Android 6.0.1 Marshmallow?

[andfo]

My Nexus 6 phone says

"This software update will upgrade your Nexus 6 to Android 6.0.1 Marshmallow, which improves performance and stability and fixes bugs."

Can I just safely believe it?

Also this phone is a rooted phone. Will my phone still be a rooted phone after updating? I also changed hosts file. Will my hosts file will be the same after updating? Will there be any overwriting after updating?

 

[KOLIO]

My Nexus 6 phone says

"This software update will upgrade your Nexus 6 to Android 6.0.1 Marshmallow, which improves performance and stability and fixes bugs."

Can I just safely believe it?

Also this phone is a rooted phone. Will my phone still be a rooted phone after updating? I also changed hosts file. Will my hosts file will be the same after updating? Will there be any overwriting after updating?

You'd prolly get the best answer by asking others who have the exact same device:
http://androidforums.com/forums/nexus-6.2850/
http://androidforums.com/forums/root-nexus-6.2851/