VB6 to .Net 4.0 Conversion 3rd party tools

I think I found the best of both worlds. On Microsoft's MSDN archive they have a LINQ Entity Data Reader which will allow me to turn my EF object in to a DbDataReader which can be passed in to SqlBulkInsert.

I would suggest that organization may be more important than separation. Separating things into separate DLLs could be useful when a client library only needs part (but not all) of the total functionality.

My suggestion would be to follow the DRY principle -- don't duplicate code. Shared code can be put into a base library that is shared among the more specialized ones. Just be careful that you don't get yourself into a dependency/DLL hell where you have to mess with an entire dependency tree...

To get around the DLL hell, I would recommend creating a single solution (.sln) file for the whole thing, then break down the separate DLLs as projects within it. That way you can rebuild everything at once, but still have some flexibility.

Another thought: as you work through your code base, you may find that organizing by business use case might not be as effective as by type of functionality or something else.