I used AVR today at Windsor - Detroit ambassador bridge. I was bit nervous, but the experience was extremely smooth. It was no different from paying a toll fee. I gave all our passports with expired visa and new passports without visa, i797 for myself and dependents with valid i94, yellow slip given by CBSA mentioning landing. The officer just asked my nationality and where I was from US before getting those documents. While giving my passport, I just mentioned to him that I need to use AVR.
He kept them inside the booth for a five - ten minutes, and returned back saying all set. That's it. We were done. Passports were not stamped, and we didn't get down from the car either.
And for those who did AVR.. one question. When I checked online i94, it still shows old date and last port of entry that I did using visa. But today's trip got updated in travel history alone. Is it the same for you guys too? Or should the i94 be updated too online? How could we know that we were admitted correctly?