Good. At this point we know everything about exception types, what they are, how to obtain them, how to compare them (at least directly). All of these have suddenly become relevant now that we have GETLASTERROROBJECT function in NAV 2015.
But an old friend is still around, the GETLASTERRORCODE function, what about it? Why do we need to bother with GETLASTERROROBJECT when we have a simpler approach, with less peeking into inner exceptions, less reflection, less spooky, obscure .NET internals?