I had the same "problem" and now i'm using a Sandisk 128GB Card in my New 3ds XL.
With this card i have no problem keeping all the good games on the console and the loading times are nealy the same as with the 64GB card.
So i would say it's totally worth to use a big card.
With this card i have no problem keeping all the good games on the console and the loading times are nealy the same as with the 64GB card.
So i would say it's totally worth to use a big card.