Depending on the particular movies, not all movies have two editions, only certain movies have two editions (e.g. Wall-E: one withoutout Digital Copy & one with Digital Copy).
Also some movies come together with the Digital Copy, meaning there's only one edition (e.g. The Nightmare Before Christmas + Digital Copy)
BD live is optional regardless if the movie comes with DC. For me, whenever there's another edition that comes w/out the DC...I'll get that for sure. Not only it's cheaper, I have no use of the DC. Probably it's useful for those having laptops & travel a lot for convenience purpose.