I got mine yesterday and used it for maybe four or five hours and actually held my hand over the top to see what the heat situation was and only during my first couple hours, downloading a TB of games was there any noticeable heat. Actually in game play use, nothing noticeable.
Its also dead quiet. Not a sound. It’s really quite amazing how well they have built it.
The most jarring thing was when my son started playing Warzone on his PS4 in the living room while I was on the den with my XSX. I heard the fans and thought, "well thats new" as I got close to investigate. I did not seem to notice anything, until I got the idea to open my door...
It was then I realized that what I was hearing was my son's PS4 blasting off in the distance. Three rooms away with the door closed...I could hear that thing going ham. I thought to myself, "Is that what I have been dealing with this past gen!?"
It really is jarring just how quiet these new consoles are. Especially when you hear a direct comparison after being exposed to silence to the better part of a week. I cannot speak for the PS5, but the Series X is extremely well designed from what I have observed first hand.