The fact that the Pi fits inside the case and everything fits nicely is obvious, as it is the official product. So far so good. However, I wouldn't recommend it overall. For use as a PC, it's not even up for discussion, either it overheats or it makes noise.

The Pi 4 gets hot, it's not like the older models. I have the 4B with 4GB RAM, with the latest firmware (December 2020) that improves power management and reduces generated heat, and with a simple heatsink on the processor. Without the case, it runs at around 50 °C in idle mode. Putting it inside the case raises it to 60 °C as there is no ventilation at all. When it is asked to do something, as expected, it quickly reaches 70°C and continues... Note that at 80°C it starts to automatically throttle the CPU.

I installed the official fan to turn on at 65°C and it brings it down to 60. But even this is not a good solution. It is small and makes a little noise when it's running. It's better to use an open-type case/stack.