Google Play Services: Google Android Project or Github Plug-In?

Dear wizened community,

I have had a search through existing forum posts, but none have satisfactorily answered this question.

I would like to implement Google Play Services into my Unity Android game (achievements and a leaderboard).

My question is as follows, what's the 'best' way to implement Play Services?

Should I:

1) Utilise the Unity Plug-In linked to from the Play Services web page

or

2) Save my project out as a Google Android Project, then implement Play Services using Android Studio (I assume this would be an alternative method)

or

3) Do something else entirely?

How have you approached it in the past? What has worked / hasn't worked for you? What should I do to just get something up and running?

Many thanks in advance,

Asa.