A lot of the early built-in auto nav systems are surprisingly difficult to use. Also, like all maps they need to be updated, and with earlier models, it was expensive to update.
My sister bought an Acura TL sedan over 10 yrs ago. Two years later she discovered updating the GPS would cost her another $350! It was cheaper to buy a stand-alone Garmin GPS so she did that instead. She could buy the TOL model Garmin with lifetime free updates for that much.
One of the features I specifically looked for in our recent new car purchase was an easy-to-use nav system. Ours is voice-activated (you still should be parked to use it safely, btw) and excellent for 90% of the driving we do, which is to urban addresses. Satellite tracking allows traffic updates through Sirius XM. Map updates are roughly around $60, depending on your car model.
I still keep my Magellan GPS, however. It's superior in storing addresses - on our driving trips it's not unusual for me to store 25-40 temporary addresses in it, set up either by itinerary destinations or geographic region. Also, the Magellan has an easy-to-use "least freeways" alternate routing that has sent us on some breath-taking back roads. It always gives estimated destination arrival time based on vehicle speed and traffic advisories, which has saved us on more than one occasion. The Magellan ETA is a touch more accurate than our car's built-in nav, and has a more active "traffic advisory: do you want to re-route now?" feature.