I was the same. The moment I saw the three icons gone I rolled my eyes. I thought it was pretty user friendly as is. That said once demoed I am interested to try it. I would like to have an option to toggle back though if desired because...

When I see UI changes like this my initial concern is not for myself but for my 75 year old mother. It has taken her years to be able to move through Android with some efficiency and the basic consistency has been a good thing. A fundamental UI change like this isn't as easy for users like that to adapt to. I am already dreading the first time she has a Google P based phone. I hope to be proved wrong.