For my money they've pushed a fraction too hard on the CPU power. One of the best things for me about the 3 is that you don't need to worry about cooling the way you do with the 4. I get why, there's a huge demand for the 4 to be able to handle proper desktop applications, but I'd love to see a version that has the thermal characteristics of the 3 with the IO updates of the 4.
I'd actually like a new version of the Compute Module with the PCI-e lanes exposed (the more the better). That would be a real game changer for NAS systems.
Or, for both CM and the full RPi, a docking header and a corresponding tiny module for a real-time clock module if not outright embed one. It's 2020 ffs.
