Most (many?) nuc users use the mini-pci flash storage devices. My NUCs (I have 3 of the skylake ones with 32G of ram) have 250G Samsung SSDs and those suckers just scream.
Its nice, though the performance of usb3 is... less than optimal the fact that I can saturate gigabit ethernet means I don't care too much. Local compiles are crazy fast though.
Its plenty fast for all my needs, though nfs over wifi is... slow in general its fast enough to not care a whole lot. I have a few bhyve linux vm's running that just go straight to the ssd's so they're silly fast with like 3g/s read speed or whatever. Its more than enough for all my home needs.