Not in stock directly which probably means resellers have an even longer wait than normal. From the installation instructions it requires the alternative 2011 LGA backplate (provided with mobo) to be installed for this block versus the standard block with the R4BE using a typical EK block.
If this came out back in November I may have bought that monoblock instead for a tidier loop and less expense of CPU block, MOSFET+Chipset block, plus the extra fittings, extensions, and tubing.
Perhaps this is more of a benefit to acrylic 3/8 loops with less flow than typical 5/8-1/2 loops? From the images it appears 19/13 fittings would not cause issues with it being well spaced out versus standard blocks. Normally larger fittings require adaptors or angled extensions.
I can see this would work very well for system sellers such as OcUK, with less man hours for installation and testing and overall costs a little less.