That was my second reaction. I personally prefer to establish my position by taking a resection, but cross checking that against a GPS is only prudent.
GPS comes into its own if something untowards happens, like the weather clamps down and you cannot see anything that allows you to determine exactly where you are.

The other point that I was trying to make was:
If you wind up having a ODTAA day, take a hint. There is always tomorrow.

ODTAA - One Darn Thing After Another.