New pen works well for corner tracking.

[starstreak]

Attached is a video from the MS store on a Surface Book, but worked the same as on the SP4.
Sorry if it's hard to tell. Its amazing how hard it is to video with one hand, view the screen at an angle and see where the pen tip is. Lol. But it tracks well. But it seems to lag the same as my SP2 when I moved it across the screen.

Pen tracking

 

[starstreak]

For me this was a big thing. On my SP2 if you got within .5 inches from the corners, the tracking would be off. It was stupid to click on menus on the corners.
This looks like a win to me. Too bad the tip looked destroyed already from customers stabbing the screen.