Mine has landed as well!
A couple of first impressions in comparison with my GRD III.
The GR is:
+ Noticeably faster to turn on, it takes GRDIII approx. 2-3x as long to be ready to shoot,
+ Faster to focus; checked outside with good light this thing is FAST, in a darkish room was OK, for sure better than my X100 was,
+ The finish on the body is rougher, less slippery,
+ Noticeably better grip (I have large hands).
+ weight wise it's hard to tell the difference (<40g)
What I don't like so far is that the front wheel doesn't protrude as much as in the GRDIII.
Apart of that it just looks lovely, like any GRx camera. I think this is the beginning of a beautiful friendship 🙂