I think the core of COM is sound (pure interfaces, QI, refcounting, IDL). I think the ugliness is due to threading issues and being welded on to Win32 message

I think the core of COM is sound (pure interfaces, QI, refcounting, IDL). I think the ugliness is due to threading issues and being welded on to Win32 message pumps. If you have a dedicated COM thread/pool you'll mostly be fine (security stuff can still get complicated). But on the other hand if you start doing COM things on a thread you own where you share control of the message pumping, you open yourself to a world of mental anguish.