This is after you installed all the same apps, logged into all of them as well, and allowing sync to occur like prior to clean install?
I didn't install all the same apps, probably 95% of them, I'm not sure that made that much of a difference ( I have a lot of apps). I put all my accounts back and they all synced like before. I also logged into the apps I mostly use like before.
I don't consider the prior original install/setup a clean one, since I transferred all information and system data from my Nexus 6. Seting up as a new phone is a clean setup IMO, that's why I did it.
So far, from my experience, the Nexus 6P battery life is a little better than the Note 5 when using it, and the standby time is less than the Iphone 6+ when not using it. That's the best way I can describe it.
I'm constantly unlocking and playing with my Android phones, were as the Iphone I only unlock it when I need it. It's hard for me to compare usage between Android & IOS for this reason. The iphone seems to shut it down even while in your pocket, and sleeps the same way when on your counter or desk at home.
I don't think I'll know my true battery life until I use this phone for a little while longer, stop playing with it, and use it only when I need it. As of now, today and partly last night, the phone has been off the charger for 19hrs. and 29 min. I have almost 2hrs of actual SOT and I'm at 32% battery. I'm happy with the battery life so far.