If any of you have already recieved your Pi 4 please be aware that there is a known issue of overheating of the unit when it is working hard . Idle temperature is around 66 Deg and throttling of the CPU occurs around 80 Deg plus .
There is a firmware update due in the next few days which will lower the idling temperature and offer a little more head room but suspect either a fan or heat sink may be need if you are pushing the Pi 4 .