Here is another specific use cases for purchasing downloadable version.

Unlike spinner hard drives shipped prior years, which you can in theory open case and install as internal drives, newly shipped drives have proprietary form factor and can not be used internally. So if your plan is to install full Audiophile on internal drive and you have a fast internet, why not save on the price difference (Downloadable vs HD shipped) and buy yourself a hard drive that will fit your computer / needs, unless of course you already have one, which makes the option even more attractive?