[Samba] Samba4 upgrade compatability

[Caleb O'Connell]

I have an existing install of Samba4 ( I think beta6 vintage ), which uses ntvfs and bind9.  It's only providing AD and Group Policy.  I have a seperate 
file server running 3.6.x.

I want to add a server to the domain running the most recent RC.  I know they are using internal by default and s3fs for the file shares on sysvol.  Can 
s3fs coexist with ntvfs?  Can the internal DNS coexist with Bind?

Is there a specific reason to use the internal now?  I'm happy with bind so if it's literally just a preference issue I'll probably stick with what I have.

If there are good reasons to move to s3fs and internal? is there an easy way to migrate the older domains via the upgrade?

Thanks in advance to everyone.

Caleb O'Connell