Both are coming out March, the Switch is coming out 2 weeks ahead of MM17's release. Choose a Nintendo Switch or a MM17 Booster Box as if price was not a factor and that both are good?
I'm getting both, but if I had to choose, I'd pick the Switch. You're going to get years of entertainment from the system and you'll spend countless hours entertaining yourself with it. The entertainment/$ is swung way in favor of the Nintendo Switch. Not to mention, you can buy singles of MM17--there is no equivalent with Nintendo Switch.
If you're not going to open the box and waiting a few years to get actual value on it. You're basically buying about $260 in lottery tickets when buying a box. You could crack value, but then you could just as easily crack Domri Rade as a mythic and redeem almost no value back. It also depends on the type of friends you have: If you have lots of interests outside of magic, then get the console, if MTG is life, get the box, sponsor draft and keep the cracked cards. Personally I wouldn't get either, maybe draft/sealed MM3 or just singles, the pack lottery isn't as lucrative unless you're lucky. Also a good friend of mine is getting a Switch so, I'll see if it's worth buying.
Art is life itself.
EDIT: Also, maybe Nintendo will make a bundle during the holiday season of 2017 too.
Special thanks to XenoNinja of Heroes of the Plane Studios for the awesome avy!
(W/U)(B/R)GForm of Progenitus, Shape of a Scrubland
BRGJund Tokens with Prossh, the Magic Dragon Foil
URGAnimar, the RUG CleanerFoil
RRRFeldon of the Third Path 2.0 Foil
BG(B/G)Not Another Meren DeckFoil
UR(U/R)Mizzix, Y Control and X Burn Spells
(W/U)(B/R)GHarold Ramos - The 35 Foot Long Twinkie (In +1/+1 counters)
UB(U/B)Dragonlord Silumgar