James-
Are any of the USB 3.0 to 4K devices available for purchase in the US? The Club3D product seems to primarily be targeted to outside the US... they list Newegg as a vendor, but Newegg does not currently carry the CSV-2302 Club3D 4K device.
--edit--
Even better, I read that the
DL-5700 is now in production which adds audio and Gigabit Ethernet and is likely to be used in 4K dock solutions... in addition to DL-5500 based products, are there any DL-5700 based products available for order/delivery to the US?