I got one K1 prototype with 4gb of ram.
Everything is working on it, when i got it, it had a google account logged in, i performed a factory reset, and have not linked another one, so cant confirm that play store is still working.
Mine is exactly that one, however mine is clocked as 2.5ghz and the device name is "Nvidia Shield LTE"
I will probably sell mine later on, does not crash, nor shutdown due to kernel /voltage issues, as the X1 prototypes, according to some reports online.
The only "Issue" with mine, is that there is no "Armor" [Faceplate] on it, and has a small crack where the Debug port is.