It was splendid.
I tapped the Passbook app, fidgeting while I excitedly tapped my shiny Gold Fifth Third debit card, and a little circle popped up. So, I held down on the TouchID button, and almost instantly, a little noise popped out of my iPhone's modest but powerful speaker, and the process was done.
So much faster than pulling out a debit card, swiping (possibly unsuccessfully), entering my pin, fumbling the card back into my wallet, and then obtaining the receipt before enjoying my food.
It wasn't totally perfect, but it was close. But also, it was really, really cool.
This is the future, folks. This is how it is meant to be. I will never pay with a debit or credit card without wishing for Apple Pay ever again.