Here is my review so far...

I like it, but it has problems. A lot of my development projects are ASP.NET. I typically partition these solutions into at least 3 sub-projects: Business/DataAccess, Tests, and Web. By having all three in the same VS.NET solution, I can easily switch between the test and ASP.NET projects.

The first problem I found with XC# is that it doesn't work at all with ASP.NET projects. So just having the add-in active causes a post-compile error to be emitted by the XC# compiler.  I emailed them and they told me that it doesn't support ASP.NET right now.

The second problem I found was relates to code generators. I really like Chris Sells' collection class generator. But XC# throws an error on the collection classes generated by it. Bummer.

I suppose I'll try it again when the next version ships. For now I had to uninstall it.