1: This is a Samba share and is exclusive to the N3DS (unless one installs the data management CIA on an O3DS), and it only works with Windows because it's absolutely abysmal.
2: O3DS transfer rates cap out around 800 kb/s and N3DS speeds cap out around 1.2 mb/s. Newer N3DS models might be faster, but I've not seen anything that suggests this.
OP, just use ftpd and one of many FTP capable apps available. I recommend ES like @Giodude, but I honestly don't want this to turn into another ignorant shitfest about "malware". It's all a false narrative.