I guess it’s subjective. There is definitely a place for single page apps, but since they tend to become quite heavy on the client I feel like they should be implemented very conservatively. For example github is a single page app (to some degree) but you barely even notice it. Meanwhile the discordapp web interface on the other hand is a heavy React app that actually makes sense, since it has a lot of content that updates in real time. But for a normal forum like this one I always feel like it’s a bit overkill. You could implement a lot of it as a regular old server-side app. That said, I’m already warming up to it. Again, subjective.
As for ‘effects’ there are many small things. Like the infinite scrolling, which is basically impossible to implement without some choppiness (I have tried…). Even something as simple as the sticky header effect can feel a bit choppy when you’re scrolling up fast. Or the fact that clicking on a username brings up a pop-up instead of just taking me to their profile.
The snow in the background is actually kinda nice. It’s quite subtle and out-of-the-way.