Review on GeeekPi 4-Layer Cluster Case for Raspberry Pi 4, with Cooling Fan and Heatsink, Acrylic Rack Case Stackable for Raspberry Pi 3B+, 3/2 Model B by Ross Decoteau

I really liked the modular design of this case. I had an old Pi and a new Pi 4 and wanted to keep them together. Of course, this case was NOT made using the mounting hole location for the original Pi (which I had to check, mine is bad), and the fan location is usually in conflict with the video from that board. However, the design made it very easy to just cut a new MDF base plate of the same size but with the correct mounting holes and flip the liner over to position the fan so it doesn't hit the video jack. Once this was sorted assembly was a breeze and it works great. With the fans running, heatsinks are not necessary in my opinion. Without them, the Pi 4 never went above 65°C at full load, and the original Pi didn't even get past 45°C, and both are overclocked to the highest possible level. The downside might be that the GPIO pins are harder to reach, except for the top Pi. I also wish there were non-slip rubber feet on the bottom. Overall I think this is a great option if you plan on running multiple Pis under heavy loads.