I just switched to a Galaxy S7 about a week ago. I had a Lumia 920, liked it, but I did try W10M on it for awhile. Had some problems with it, but also didn't like the lack of ease for one handed use. After a few months I switched back to 8.1, and then about a month later got the S7. So far I'm liking it, but I will say that the first few days were frustrating as hell, as I didn't know the OS (probably took about the same amount of time as it did to adjust to Windows 8 on my laptop). I've been slowly adding apps as I go/figuring out what I want, so I don't dump a bunch of stuff on it and then find my battery life plummets or the OS starts to lag. No problems so far. Few thoughts/observations:
Frankly, the Outlook app was just OK. (For reference my primary email account is with Yahoo, and my secondary with Outlook.) I ended up liking one called TypeApp better. It has tons of options, dark theme, and works pretty well with one hand (about the only time I have to reach is to hit send). I actually prefer this to the native Windows phone client (either WP8 or W10M). Outlook didn't have a dark theme, it was not one hand friendly, and didn't have as many options. Also, and annoying as hell, when you deleted the app it yanked the exchange connection with it, which yanked all my contacts off the phone. Not exactly want you want to find out when away from the house. I could also never get the calendar to work.
Speaking of calendar, I could never seem to get the Outlook.com calendar to play nice with the phone/apps. I eventually gave up and just imported the calendar to my google account, and use that. Best calendar app I found (after looking at some of the highly rated ones) is DigiCal. It was the one that reminded me the most of Chronos Calendar (which was what I was using on Windows Phone). Some aspects of this app I like better, and some aspects of Chronos Calendar I liked better. So overall happy with DigiCal for how I work/schedule stuff.
Chrome just didn't seem to work well on this phone. The Samsung browser is fine. Everything is at the bottom of the screen other than the address bar. And you can block ads with the adblock version of it, which makes things so much faster. I haven't played much with the various browser options though.
Still using the stock Samsung keyboard. I like the number row, but other than that the Windows Phone one is better. The Samsung one sucks at swype type predictions. Way too much emphasis on the first letter. Slightly off on that and then the predictions suck. Need to try some of the other ones, like Swift, just haven't gotten around to it yet.
Google Maps is awesome, other than not really being able to download maps (you can download them for a month, then you need to redo it. And, if I understand it correctly, if you have a data connection it just pulls it from there, so the downloaded maps really only work if you turn off data. But I could understand that incorrectly). Haven't tried any of the other options.
The camera on this thing focuses SO fast it is astounding. So much faster than the 950 or the iPhone 6s (I've played with both for a bit, and there is no comparison on the speed). In some ways it might be too fast, as I think it might accidentally focus on stuff in the background when trying to follow around a moving kid on video. But I need to play with that more to see if it was my imagination.
I do miss the ability to pin stuff to the start screen in Windows Phone. My main use for this was pining flight status from United's app (my wife flies a ton, so this was used frequently). But, the phone runs so fast, and you can pin flight status within the app, that it isn't that much of a time difference.
The one thing that sucks is Cortana. I mainly use Cortana for reminders. But she sucks on Android. You have to speak, or go through layers to set a notification (like in W10M, unlike the pin a reminder tab to the start screen in WP8). And then on top of it, there are only three snooze options (I think it is 5 minutes, 15, and 30), and whenever the notification goes off she speaks that you have a reminder. Even if you have the phone set on vibrate. Which is awful and really intrusive. This alone might make me try out google now.
The battery life is awesome, but coming from a 3 year old L920 the basis of comparison isn't really valid as that battery was toast...
Also, someone was mentioning bluetooth and texting in a vehicle a few pages back. When going through the android central forum a few days ago I recall seeing a thread on that, and someone mentioning an app that worked (might have been google now, or something else, I just don't recall). I didn't pay much attention to it at the time (not a function I use), but you might want to search there.
Feel free to ask any questions. So far I am liking the choice.