I've heard it's better than CalDAV Rated 4 out of 5 stars

Also TB has Google Calendar integration by default using CalDAV protocol but after searching through web I found out that this addon has some little more features and is easier to setup.
Plus this addon provided Google Calendar support before Google support CalDAV itself.
I gave it 4 star because it doesn't support Google Tasks syncing with Lightnings' tasks.

This review is for a previous version of the add-on (0.18).