>So, why are the calls through IDispatch? ADO supports dual interface calls
>and direct attachment to the CoClasses should provide better performance.
>

I'm not sure. Or maybe it doesn't but there is other overhead problems.

>We all know about these problems of course. MSXML has the same problem
>for parsing sizable documents.

Yes, as we've talked about recently. Microsoft is aware of these issues. One thing that will contribute to this area is COM+.