Seriously. NPM/bower downloads are at least 50% of our CI build time - which also includes compiling a largish C# solution, running unit tests, generating PDF

Seriously. NPM/bower downloads are at least 50% of our CI build time - which also includes compiling a largish C# solution, running unit tests, generating PDF documentation, building an installer, and putting everything through ReSharper code inspections. That's when those download/install steps don't just fail for some unrecorded reason.