I went in for 2 but they haven't went to be molded yet. I will post a report and photos when I get it, probably a couple of months.
Ed over at HDPS has a one/two liner on his website stating he will be making some as well.
Yes it is a US part, but even better is that they are selling them as pistols.
Hence you can legally build a pistol configuration which you cannot do with a HK USC unless you register it as a SBR, then pull the stock off and add an endcap. (i.e. like the photo under my name)
Also, 922(r), does not apply to pistols. So the rest could be 100% HK.
Here is the language so that the thread doesn't get off track arguing that point:
"922 (r) It shall be unlawful for any person to assemble from imported
parts any semiautomatic rifle or any shotgun which is identical to any
rifle or shotgun prohibited from importation under section 925(d)(3) of
this chapter as not being particularly suitable for or readily adaptable
to sporting purposes except that this subsection shall not apply to--"
The grip in the photo you linked to is a seperate piece and make by HK.
Of course if you use the receiver to build a long barrel rifle, 922(r) will once again apply.
I think for the price it is hard to go wrong.