Similar benefits to most hosted commenting solutions, most of which have to do with scale in one form or another. If you're a small blog who gets a handful of comments a month, you might not see as big a benefit (though, there are still some).

- Decreased server load.

- Reliable multi-region storage and delivery.

- More login options.

- One login account across several websites, which decreases friction whilst still providing the safety of having comments from verified users.

- Moderation filters that can act based on past user behavior, before they ever interact with your site.