The new forums are eye candy, but worse for usability.
In fact, this is a horrible change.
In most forums that I visit, the forums remember what was new at the time you visit, so that the next time you visit, you can see which posts are new, and which ones have nothing new. Not here ... can't find this feature.
Most forums that I visit have a button you can click (or this is the default behavior) so that when there is something new in a thread, you click that button and it takes you to the first message that you haven't read in a discussion thread. Not here ... can't find this feature. If a thread has 12 posts, only 2 are new, I seem to have to scroll down to find the new ones myself. Terrible.
Computers are good at remembering things. Seems you have decided not to make use of that feature.