I’ve had my Nexus 5 for a couple months now and it is a very good phone. It has been rock solid and very quick. I think you will like it.
I use a program called Adfree and I have practically no ads on my device note. It does require you to root your phone, but for the Nexus 5 that is not hard.
I thought they preferred the term “Artificial Person”? 
My phone arrived today and I set it up this evening. So far my only dislikes are that I don’t like how Google Voice uses the phones dialer which makes it feel confusing and that it is a bit if a pain switching between languages. I like the way the iPhone has a little button in the keyboard that makes it easy.
I prefer this phone’s method of opening web links in a browser rather than handling it in app. I like that it is easy to move within a line to edit. I love the way it handles email notifications.
How do you turn off sounds for emails?
Go to Gmail, settings, and select your account. Then you’ll see notification settings.