I think I will buy digitally for the 3DS version. Having it accessible anywhere will be very convenient. I might buy the physical version later though.
Sticking to physical for the Wii U version, in case someone I know is crazy enough to own a Wii U but not Smash. Plus for collector's value.
SteamID: bulby1994
3DS Friend Code: 5112-3450-2144 | Nintendo Network ID: Bulbousaur