What’s you gut answer right now; without reading the rest of this post?

In my (seemingly) never-ending quest along the path of Uncapacitated Facility Location problems, I found myself thinking if I would be better of write some core functions in C (unmanaged) and calling them in my VB.net project? I thought that it probably would be, but decided to check first. Here’s the link, you can skip to the conclusion at the end for the low-down:
http://www.grimes.demon.co.uk/dotnet/man_unman.htm