When connecting to a replica set with slaveOk=true the C# driver currently waits for responses from all servers before returning. This can cause a long delay if any of the secondaries is off line or responding slowly. Instead, Connect should return as soon as the primary is found. At that point it may or may not know about any of the secondaries yet. As further responses from other secondaries come in they should be added to the list of known secondaries.

This is not a problem with slaveOk=false, as in that case it is already returning as soon as the primary is found.