Interesting. That is exactly the route I have gone through: Setting up Active Directory with Samba in a mixed environment (Linux servers and Win 7 clients). I now happily run Linux Mint clients connected via sshfs.

Setting up Kerberos was a nightmare. Also, it is very hard to reason whether your SMB connections are safely encrypted with the specific settings one chooses. The protocols are complicated and the settings opaque. A lot of Stack Overflow is involved.