Since this is just an incremental processor upgrade (speed) and no other changes, the MBPro M4 will continue to work for me. I had hoped the M5 might bring TB5. Meanwhile the M4 MBPro satisfies my need for a general purpose, coffee table machine with a decent number of ports, an SD card slot, excellent screen and reasonable (for a laptop) sound. The only other things I would like in an upgrade is the current specs in a lighter machine and even better battery life. And an MBA does not meet those criteria due to it's lack of ports (USB and SD), poorer screen quality and terrible sound (I know since I have had both the 13" and 15" MBA in the past).
My next upgrade will be to replace my 16" M1 Max MBPro which has 64TB of memory and 4TB of SSD. For that I am looking for a lighter machine as a top priority and a physical appearance update would be a nice but not a game changer (the current machines look too industrial to me but this impurely aesthetic and I am more interested in function than form). An OLED screen would also be nice but not necessary as the current screen has excellent color accuracy and is more than bright enough but may be needed to get more efficiency with a smaller profile battery.
