1) Very fast loading from cold boot of (any system). I don't like to put my system on idle or sleep mode, so I think this would benefit folks like me.
2) The way Playstation still requires almost two reboots to patch the entire system. As soon as it is done downloading, it should unpack/install the firmware right away, THEN do 1 restart (or no restart needed if it's just a minor patch).
3) Keep all the basics in right out of the gate (Themes, Folders, External HDD/SSD support, External USB Flashdrive support, ability to dim controller light/system beep, etc.) Why are some of these features removed every beginning of the gen to get added later (or never)?
4) Keep the same disc drive, so it can read CDs, DVDs and Blurays (both single and double layer); find a single model that doesn't vibrate/rumble so much & faster read speed.
5) Continue to improve the UI, so it is as close to 1 millisecond as possible.
6) Fix the input lag from controllers + other peripherals, so that PC and PS fighting game enthusiasts stop complaining about it.
7) Make it very easy for developers to go back and update older games. I know PS did a good job, but some PS4 games (both Indie, B, AAA) are wonky on PS5, and they don't take advantage of the Dualsense, VRR, or (at the very minimum) SSD load times. I want this to be a non-issue when PS5 games are running on PS6.