You know I downloaded and read that white paper a while back it was really helpful. I did just read in this book I have from Microsoft Press that relates to:

COM usage in .NET - States that COM let properties that you where able to assign in VB 6 are not readable in C# but they are in VB.NET.

To me that is a big downside. Because I use & develop COM components all the time. So I would have to modify those components for use in C#.

I would like to point out that the .NET Framework does integrate nicely with COM. The architecture for building COM readable components in .NET is nice.