The docking computer demands too much attention. When I'm doing exobiology, I need to turn it off because I prefer to land manually on the surface. The first landing doesn't go as expected because, as you can guess, I often forget to turn it off.
When I drop to a station, it should be turned on. It often happens that I approach the station, request docking, throttle down, and go to make a cup of tea, only to find the ship still in the same place because I forgot to turn on the docking computer.
The DC is a pain in the back, so I've stopped using it. The only place I have ADC is probably on my T9 for tritium services.