Just checking one of the bigger threads, and although the system places the reply immediately under the post it's replying to, it doesn't indent any of the posts or sub-threads, thus making it a bit harder to see what's happening.
I'm used to either the way the Newsgroups worked or how places like GG worked. With GG all the posts are in chronological order and you simply read the bottom posts, it works as most have the post it relates to quoted in it. With the newsgroups they indent each post level, thus the posts created a clear hierarchy you can visually follow to see where each new sub-thread or sub-sub-thread starts and ends. Because posts are chronological within the sub-thread it replies to you often have a 'new' reply set in the middle because it's a response to the post just above.
What this does is a sort of mix of both but doesn't show the hierarchy, thus it's extremely easy to miss a reply because it's in the middle of the thread. Not nice and hard to follow.