Directory Programming .NET

What is the most efficient way to determine if an object exists? I have found many posts saying that DirectoryEntry.Exists is unreliable and does not support passing credentials.

I used to check if e.NativeObject == null and an exception would be thrown if the object didn't exist, however, now I'm trying to switch to FastBind and the exception is no longer thrown.

If you want to move the least data across the network as possible and want to use the DirectoryEntry for this, then a RefreshCache operation on a single small attribute is likely the best bet.  Using the DirectorySearcher is also probably as fast, especially if you have already established a connection.

I do generally recommend avoiding the Exists method for the reasons you already stated.