Rated 3 out of 5 stars

The add-on seems to do what it was intended for.

However, I hope in the future it will be possible to sync multiple Outlook.com accounts, each one to their own address books (similarly to the gContactSync add-on).

This review is for a previous version of the add-on (1.9.8.6). 

tzpush2-beta does this. It is available under other versions.
Let me know how you get on at https://groups.google.com/forum/?fromgroups#!forum/tzpush
Mark