I created an account on wordpress.org just to rate this plugin.
When G+ comments came out I saw a few plugins made that day, all looked kind of risky and not great. Those all still have just a couple reviews, while this one has clearly taken off.
This is done right. G+ comments work. Facebook and other social comments added which makes sense because no matter how we feel, people use other media. Conversation anywhere is the goal here.
I wish G+ had a notification system on this. Hopefully eventually. If anyone has any clever way to find new comments please let everyone know.
Also I would up vote adding some styling support. Looking at the G+ code it's kind of hard to follow so no fault on the dev but if he could figure it out, +1s for everyone.