Well, I finally made my first NFC transaction with the Nexus 7.
I had never used NFC or Google Wallet before and I had trouble getting it to work the first two times I tried it. The first time I'm pretty sure the restaurant's NFC reader was bad but in the second instance I think I must have been too impatient.
For me, the only way I could get Google Wallet to work was to have the app open on my Nexus 7 and to have already entered my PIN code. I've read that most people only need to have an active screen and Google Wallet will open once it's near a NFC signal. I'll have to keep trying....
While the whole NFC transaction is pretty fast, it seemed to me like it takes a long time before anything starts to happen but once it starts to happen it goes fast. By the time I hear the Google Wallet tone the cashier's telling me that everything's OK and I've paid my bill.
On a final note, there's some entertainment value associated with buying lunch with your Nexus 7. The cashier at McDonald's was impressed and then stated she thought the Nexus 7 was just a really big smartphone.....