OpenRigs is huge so i dont like them, these are much compact.
We tried smaller versions, but when you reduce the space between the cards significantly you may as well not even bother. The heat map at 6cm (back to front spacing between cards) is horrible compared to 8cm. The whole point of an open frame is to let the heat disperse naturally and evenly. When we have some time we'll be put up thermal imaging (FLIR) photos of rigs running at different space points to demonstrate the heat dispersion at more compact intervals, but trust me when I say that more compact is non-optimal:)