Disqus is a great idea turned into hot garbage by (inevitable) lowest-level monetization. I once worked on a blog with Disqus. Whenever we had a hit, such as an HN front page, horrific ads would be injected into the comments section for that page. Any page without significant traffic had no ads, lulling you into a false sense of security. If a page 'hit' in your off-hours, the ghastly and repulsive ads could be running for a day, or even a weekend.
They could be turned off at the time but only on a case-by-case basis. In the end, I got rid of Disqus.