NSIS is Cool!
1. Give the user the option to not install to the GAC
2. Give the user the ability to choose what optional components they want installed.
All of this done without the headache of creating custom actions & trying to figure out how things work in the limited MSI Setup Packager within VS.NET. I definately suggest this free script creator as it is very, very nice, to all developers out there struggling with VS.NET's MSI Setup Installer.
The only problem I came across, was how to install stuff to the GAC, but Martin Webrant gave me a good pointer. I also built in support for detecting the .NET framework & its versions. If you're using NSIS, or want to get started and need some pointers for installing .NET assemblies, I'd love to give ya some help and give you some of my functions.