I am basically digital only for my Japanese 3DS since I cannot be bothered risking the import fees and my 32GB is far from being filled. Full of digital titles, demos, videos and I've never had to delete a single thing.
Just in case nobody has posted about this, you can make a substantial saving by buying the New 3DS on Amazon France. If you wait for preorders to end and it's actually in stock to be shipped, you can also have Amazon convert the currency for you and avoid all the foreign transaction fees and it'll only take 2-3 days to arrive with their €1.50 shipping fee. You can save over £30 with the regular edition.