[Josh Mackey]

The accuracy of the pen on my surface seems to be hit and miss. Even after calibrating it a few times, it still seems to be off. Its even worse in the top left corner where the cursor point gets offset quite a bit.

Anyone else experiencing this?

[pdch]

No, but I have noticed that you have to hold it pretty much straight up and down. Mine is accurate anywhere on the screen. You may have a bad unit. I believe the Pro has a matrix of wires that generate the field for the pen, maybe you have a broken wire.

[zhuz]

I have the same issue with using the pen at an angle in the corners, especially the top left. I think it's not an isolated issue.

However, I did get better accuracy after increasing the number of calibration points. Here's how:
Improved Pen Accuracy with a 100 Point Calibration Grid : Surface

[Josh Mackey]

No, but I have noticed that you have to hold it pretty much straight up and down. Mine is accurate anywhere on the screen. You may have a bad unit. I believe the Pro has a matrix of wires that generate the field for the pen, maybe you have a broken wire.

That seems to be the case, I can see a rather large precision drop on the left side of the screen.