Overall, I haven't had any particular issues for my use of Google services on the 1520, and whilst some of them aren't as smooth as on android, there are non-google options that I've found that are functionally better for me; more portable and integrate more effectively with other apps that I use. What I use is affected by needing to work over multiple OS's. If I was living in just WP world I'd use Microsoft only; if I was living only in android I'd use Google only; and if I was living in iOS only I'd use Apple only. Of these three I've found cross platform integration easiest with Microsoft. The lack of cross platform integration is leading me away from certain google services to more versatile options. These are my experiences with the different google services that I use/have used:
1) gMail: fine for me. There's no swiping to the left/right in WP (which I prefer on iOS compared to the android version of gMail). But the conversation layout in WP for gmail is one I prefer over even the android gmail layout (also suits my corporate email very well!).
2) Google search: No problem for me- there's a Google search app on WP (from Google). However, I'm using Bing more and more and I'm surprised at how good it is. I stopped using google now a while ago because it got in the way of what I wanted to do on android and wasn't given me the specific information I wanted. There are other android apps that gave me what I wanted.
3) Google Maps: these are available on WP. 'Nokia Here' is excellent and I was surprised at how much better driving instructions were with Nokia Here compared with Google maps/navigate for my journeys.
4) Youtube: works fine. And there are 3rd party apps on WP that make downloading clips very easy.
5) Google+: this is the one thing where I notice more of a gap between the Android and WP experience. It works smoothly enough, for posting, reading notifications etc. However, I hadn’t found out until this evening how to reply directly to someone (as opposed to putting a comment in the stream of replies).
6) Google contacts: Not a problem for me- a while ago, in order to sync my work contacts more effectively I'd merged my contacts from hotmail into google; deleted them from hotmail; exported from Google (google.csv)and imported into hotmail- using that as the master over iOS and android; with subsequent changes in any other address book being linked. To date that seems to have worked ok. Though having a quick check it looks like if you simply select google as a WP account and select to use Google contacts it doesn't bring over all details- google and outlook appear to have slightly different contact fields. It hasn’t caused me an issue to date- I need my contact details on iOS; Android and WP (as well as in hotmail and google).
7) Google docs: No problem for me- I use MS office on WP. And even on Android I tended to use Kingston office rather than google docs.
8) Google Drive: No problem for me. I use gDrive on WP through 3rd party apps. However, I am starting to use Onedrive more and more and I use Box mostly. I have more storage with Box than gDrive & Onedrive. And Box has better integration across the range of apps & operating systems that I use compared to gDrive. My photos are auto loaded from WP into OneDrive which is fine as I've had less issues sharing photos using OneDrive for access by relatives than I did with Google photo albums. I have some relatives who only use Microsoft; some only using iOS and some only using android.
9) Google Calendar: I stopped using google calendar a while ago as I wanted my appointments in one place & my work calendar prevented use of external calendars (so I started putting most of my personal appointments in my corporate exchange calendar and marking them as private). I still have a few things in google calendar which come through ok (though there's something that doesn't feel quite right if you use multiple google calendars in one google account on WP- specifically if you add a new google calendar. (I used the multiple google calendar feature a lot when it first came out but stopped after a while as it was a level of complexity that I didn’t need).
10) Google keep: I stopped using this a while ago. It wasn't accessible on iOS easily and I need notes portability. I started using Evernote and OneNote for short as well as long notes and haven’t looked back!
11) Google tasks: I long ago abandoned google tasks as it didn’t have the functionality or integration I was after. I use 2day on WP which is my favourite to-do app, ever. And it syncs seamlessly with Android and iOS to-do apps (via a free todoodle cloud account).
12) Google music: I use Amazon and iTunes as music from there was more portable than google music used to be (and looks like there's a WP app to access Google Play).
13) Google News: not something I ever really bothered with, preferring Flipboard for news. However, on WP I've started using Bing news which I prefer over Flipboard (it's one of the places where the 1520 's screen size and mouth watering screen come into their own).
14) Google translate: I never really used that much. Wordlens is great on iOS and Android. And there's a decent equivalent on WP (Bing translate).
I don’t want to switch totally into just Microsoft or Google. But for anyone wanting to look a bit further I just found this: http://www.windowsphone.com/en-gb/how-to/wp8/basics/moving-from-android-to-windows-phone