I've been using a 920 for a week. This is my "try out Windows Phone" test, I've come from a Samsung Galaxy S3, and just because I was bored of android really, and wanted to try something new. The 920 is heavy, so not a phone I would keep long term. I find most of the Nokia Windows phones quite chunky, so I will be interested to check out the 1820 when it is released, see if that is any better.
I use Google processes heavily for work, shared calendars etc, so had to find a third party calendar that synced with my Google calendar, it cost me ?1.99, not a problem. I'm not too sure about using a 3rd party app to access my Google Drive files, which include finances, so I just wait until I am before my laptop for that work, again no problem. Prob too fiddly to do that on a phone anyway, and I only very occasionally attempted that on my old phone. So not a biggie.
The phone and interface is fast, no lag like I had on the S3. Google calendar and Drive aside, there's only 1 app other I had on android that is not in the Windows Store, or there is no equivalent for, and I don't think that's too bad really?
I *really* like how the phone can pick up pictures from my Facebook a/c randomly for the lock screen, gives me a nice surprise each time i wake up the phone
The way the settings are laid out is simple, compared to android where you could get a little bit lost in menus trying to find the right setting. I also *really* like the double tap option to wake up the phone from standby. Pictures are automatically stored to my SkyDrive account from the camera, and the Office365 facility is useful, although I havent yet and prob wouldnt need to use it on the phone, is handy for if ever I did need modify a document.
I wasn't too sure about the notifications, or lack of - used to my S3 blinking at me when in standby mode, letting me know I had a message or missed call etc, so initially I was very worried that I was going to miss everythng with this phone. But then I found the Glance option in the Settings, and configured my lock screen to show the notifications I want, so all fine now in that respect. I understand there will be a notifications centre coming in 8.1 too (and Google Calendar sync!), so even better. I do still miss the ease of notifications in android though.
This phone seems to use less battery power than my android phone when in standby, which is good. Less bloatware than android for sure, and makes a difference.
Overall I like the phone, but, I do find myself missing android, which surprises me. I think it's the android notifcations bar more than anything, just what I am used to. Probably also that this phone is heavy and chunky, compared to the slimmer android smart phones. I'll wait until I can check out the notifications in 8.1, but at the moment I am keeping my eyes on the new phones about to be released, and leaning towards a return to android.