Well this thread scared me with the horror stories but I used my physical gift card that with zero issues at Courtyard Vacaville (paid in full) and a Fairfield Rohnert Park (paid partially). The staff processed the payment super quickly and easily. I even commented to the clerk at the Vacaville that I had heard that GCs were harder to process but she was like nope, it's super easy. Now buying said gift card at a Delta was quite the ordeal, taking about half an hour for the clerk to process.