I used it as my main DE a few years ago, its great! Really cool UI, completely different to all other DE's but it makes sense, and it has some cool stylings like for example virtual desktops icons being the actual desktops, just really tiny. The bugs, however, kept piling up, and it (segmentation fault)ed too often, so I had to abandon it. Last I heard, the reason it doesn't get major dev work anymore is that its really hard to work with.
Twenty years ago, you'd run it every now and then because it was kind of fun. I'm not sure if it counts as actually using it though. There were actual window managers for that.
I'm not sure what the use case is nowadays, I'll have to install it someday.