After a few days some thoughts.
Battery life is fine, about the same if not a bit more than my Nexus 4; about a day and a half on a full charge. I REALLY miss the inductive charging, but I guess that'd be hard to do in a metal case. Apple isn't making a dock either (or hasn't yet), though there'll be lots of 3rd party docks I'm sure.
I find the add-on keyboards a bit wonky, they seem to randomly change from my downloaded one.. or maybe new apps or uses need to choose the new keyboard and it remembers it? Either it's wonky or I haven't figured out the pattern of the feature. It also switches to the Apple keyboard for password fields, which I guess makes sense in case the keyboard maker decides to steal passwords.
Had some issues with the Gmail app not sending notifications, and Chrome scrolling (the amount it moves from a flick and how long it takes to come to rest from a flick) seems far lower than Chrome on Android or any other app in iOS. Insert Google conspiracy to get people to go to Android here, shades of "DOS ain't done till Lotus won't run"?
But getting everything else back up and syncing (Google calendars and contacts etc) was nice and easy.
Back to iOS from Android
As expected there are some things that I'm glad of and some things that Android does better (and some things that are simply different and take time to get used to). The notifications on iOS are better than before but I think I still prefer Android's, the row of icons at the top to show me unread mail, apps pending updates, alarms slept, was more informative at a glance.
# of actions (swipes, taps, etc) in iOS is generally higher than Android which is what I recalled going the other way.
Overall happy with the phone