it's underpowered compared to NUC's (and similar) in it's price range, even after adding hdd's and ram to the NUC kit if you don't buy it pre-made.
the top $1k model still is only a dual core cpu.
it comes with a slow 5400 rpm drive instead of a ssd. even the pro $1k model has a slow 5400 rpm mechanical drive unless you pay extra for the upgrade.
not to mention thunderbolt ports have not really caught on outside the apple-peripheral community, would have liked to see more USB3's than thunderbolts.
(also not sure about their claim of "lowest power computer in the world", guess it depends what your definition of a computer is, because RPi takes 700mW. None-the-less, some of the NUC kits sip only 8W or less, while the new Mini is rated at 83W)