If an application relies on the workstation being logged in, NWDSOpenMonitoredConn can be an effective API to use. It will fail if the workstation is not logged in and it will always return a connection to a server with a read/write replica to the logged in object. This will be a performance enhancement if the application is going to work with the logged in user object.
Because NWDSLogins are relative to a NDSTree, the 'Monitored Connection' created is relative to the NDSTree. A workstation (user) therefore will have a 'Monitored Connection' for every tree it is currently logged into.
However, with the NMAS login methods, like Universal Password, this call is typically bypassed.