Windows 2012 automatique schema upgrade function

Hi everyone,

I am wondering about the automatique schema upgrade function in Windows 2012.

The fact is I have a simple AD domain with two DC 2003 R2, functionall domain and forest level 2003.

I want to install Win 2012 DC so i can simply add it and promote it will  automatically upgrade the schema. 

But with previous version (2003 to 2008 R2) i used to isolate a DC, play the schema upgrade manually, check and re-join it to the infra if the procedure was ok.

It was a safe mode but now with automatique upgrade i don't know if this is really necessary.

What do you think ?

Thanks,

Regards,

julien