I received mine: i5 256GB. Installed the necessaries. Very fast. This was an upgrade from an SP3 i3, so I'm easily impressed.
One thing concerns me: I've had the screen shake (meaning the whole desktop moves to the right briefly) and the screen blanking. It's happened a few times under very specific conditions. OneNote, for one. Also, scrolling through face book very predictably produces this. In addition, occasionally the screen will turn just the tiniest bit blue. Same conditions. That happens opening this very site, in fact. Also scrolling through facebook. I'm trying to decide whether there's a problem with the screen or some sort of bug. It's very odd. I can demonstrate if anyone's interested.