Official comment
The NXS2 (and all current products) are only USB2.0 as the maximum bandwidth of four 24bit/96kHz WAV / AIFF streams (4608kbps per stream / 18432kbps for all 4) are still well below the throughput of USB2's theoretical maximum of 491520kbps).
Why you want to buy a USB3.1 (or 3.0) device to store your music is the write speed from your computer. Why sit around waiting for music to export when you can purchase a high-speed drive that takes mere minutes to write gigabytes worth of audio?
Yes, the SD max is 32GB on an SDHC, those are convenient for size, but not performance. Go with a fast USB drive instead.
As I posted in another thread the other day...
Personally, I use the SanDisk Extreme Pro or Corsair Flash Voyager GTX USB drives as both of them have SSD controller chipsets to manage the memory for amazing read/write performance. They are certainly more pricey, but that cost is well worth not waiting around to export music to the device.
If you're going to that price point, you may also want to consider the Glyph ATOM, and the Samsung T3, two reasonably small but ridiculously fast SSD drives.
