2020 M3 or 2018 MS

We currently have a 2021 MY and that is our only car. Planning on getting another Tesla as we have a Tesla Wall Connector at home. I've been looking at both and checking threads and such, but wanted to know if anyone chose one over the other. I'm leaning towards a Model S as I've wanted one since the 2012 model came out, but I know hardware, charging, and mileage have changed a lot since. I telework mostly so mileage isn't really a problem, but I'm having my first kid in late Feb so I need something that is safe. I can push for a 2020 MS as well, but not sure if it's worth it for the extra money. Any advise or insight would be helpful!