My normal habit when visiting this forum, developed from using the prior version of the forum software, is to open each subforum, then for each thread with new replies, right-click on the "go to first unread post" icon and open it in a new tab, and repeat for all new messages in all forums. I then work my way through all the open tabs to read all the new messages.
Recently, I tried using the "View Unread Threads" button to see if it would at least save me from navigating to each subforum individually. It does, sort of, but it doesn't seem to work right. It appears to have two issues:
1) It doesn't seem to list the unread threads in any particular order that I can discern. They're sort of in chronological order-ish, but not exactly. And they're not grouped by subforum, either. I really don't know how they're ordered.
2) Even though the "View Unread Threads" list has the same "go to first new message" icon that I'm used to seeing, clicking it doesn't take me to the first new message...it takes me to the first post of the thread, every time.
So, I'm back to opening each subforum and looking for new posts that way.
This newer version of the forum software is much better than the older version, but it's still kinda janky compared to other forums I participate in (phpBB, vBulletin, XenForo, etc.)