I think you're better off with the portable skill set. It introduces you to the non-Microsoft way of doing things, which in my experience is usually for the be

I think you're better off with the portable skill set. It introduces you to the non-Microsoft way of doing things, which in my experience is usually for the best. What are some examples of unique/better/amazing things that .NET does? And what could make it worth requiring Windows to use? If it's just yet-another-way-to-do-X, and Windows-only "for no good reason" (and Mono doesn't count), then you have your answer. Money is tight, especially in a startup; if I am to invest in Windows, it had better be to enable some outstanding technology that will genuinely give me a leg up on the competition.