The bigger issue is that nesting is a poor format for displaying comments, once a discussion gets large enough. I've been a part of the team revamping Huffington Post's discussion interface, and I think it's a great solution for giving people the option to switch between breath-first and depth-first exploration of the comment tree as they see fit. It's not a perfect solution, but I do think it beats some of the worst problems of nesting.
I think it is horrible to use. What would have been better is use the same system but without this horrible pop-up window.You can totally open/close a comment tree without having the feeling you are going to a new page just to see the comments.
I think the way disqus works is a good compromise.It's perfectly ok to limit the depth of the comment tree to 2/3 sub comments no more.And even limit the number of sub comments.
There are a lot of other stuffs I hate about the HuffPo ,the fact that HuffPo tries to trick you into clicking the same link multiple times by changing the title and the picture of an article I already visited makes me angry ,it's just click bating ,and makes me feel HuffPo thinks i'm an idiot, i dont have time to waste with these tricks,and I think it's borderline dishonest.
Anyway that was my little rant about Huffpo UX. I really wonder if your userbase is growing thanks to these choices. People use to come to HuffPo for its content, and there is a lot to say about its quality too today.
I find Disqus great for content with only a small amount of commentary, but extremely unpleasant to use on articles that have more than say 400 comments (and CNN regularly has articles in the thousands of comments). At that point, if you're viewing either the oldest or most liked comments, it's damn near impossible to browse the comments that are directly on the article. I think even HN's low tech interface is better.