What did you previously have read it all on various "technical side" on the web, for example, the one needs a wrench to transfer data from an old 3DS on the New 3DS. This is all humbug. Yesterday I transfer all data via Wi-Fi. Although lasted almost 1.5 hours, but in the end were all data, including down loaded games (SMT IV and Animal Crossing), including friends list, Scores and Network ID on the New 3DS. For this you simply select before the start of data transfer "SD card data transmitted wirelessly." Note you should alerdings that the built-in New 3DS XL Micro SD card 4GB includes. So the data from the old 3DS should of course not exceed this storage volume. But this is explained basically everything beforehand. Anyone who is uncertain can again read on Nintendo.de everything for data transfer.
I like the New 3DS really very good. It is the perfect handheld for old and young. What I would have liked that Nintendo screwed the resolution of both displays at the New 3DS slightly higher. But this is probably only then to the next new HH from Nintendo.
For those who still do not know: In the standard packaging of the New 3DS / XL is no power supply. But as it has been over 10 years, all power supplies of the total DS / 3DS - family compatible with each other.