Are you wanting to drive for fun or are you hauling something? Flights are cheap compared to the very long drive.
I have only done it once and it's been a while. It was fairly smooth but a friend of mine that owned a hotel down there sold it because it started to not be quite so smooth. Baja California previously did not suffer from the same issues as driving down the other parts of Mexico but he started having problems along those lines so he pulled out. Not sure of the current state of things.