These days you don't have to choose. I run Win 7 on my machine and a virtualbox Ubuntu on that. So I develop in Ubuntu, and any kind of multimedia stuff is handled in Windows.
The great thing about development on Unix is that it is all just there. apt-get install xxx and you are ready to go. Versions are automatically upgraded. If you prefer working in a windows environment for some part of your project, you can easily do it by sharing drives and networking.