No, it isn't. First, your box will likely arrive damaged, if it has to be delivered anywhere else than the US. Second, you get the manual in PDF if you buy the download version, so you're not missing out on anything. Third, you can have the game in windowed mode and the manual open in the background.
The box will feel nice in the beginning, but over time will become just a nuisance since you apparently have enough bandwidth to install through Impulse, which is much more comfortable. Speaking for myself, I have stopped buying boxed versions of games two years ago, because I simply couldn't put up with the boxes anymore. Games that can be registered over Impulse or Steam are better, since you don't need the box afterwards, but those that can't will occupy your precious space and irritate you to endless heights, since you'll need them every time you want to install/play the game. I am even willing to pay premium for digital versions of games on Steam/Impulse just because of the added comfort.
Admittedly, this is not an issue here since you get the digital version as well, however, I would ague that you gain nothing by receiving the boxed copy.
