I tried microsoft synctoy tool but did not liked it very much.. very basic sync otions no mirror sync, in my network while sync active it hogs down too much bandwith all other network services hangs etc..
IMHO free file sync is much better
FreeFileSync | Free Security & Utilities software downloads at SourceForge.net
it has active realtime sync (can be run as service) that can detect changes, connected disk and sync automatically.
ofcourse configuration may be complex for some users but it has great help files.
it doesnt change save menu to make saves to two locations but it can sync files when folder contents changes