Until you can create custom routes in Navigation, FSD is fatally crippled. It's good for going someplace you have no idea how to get to because any route is as good as any other in that case, but if you want to take a specific route based on your experience or preference, it's a major hassle. This is before getting into any of the brain-dead stuff FSD does (*). My solution has been to choose two intermediate destinations on my normal route and use them like waypoints, canceling them as I get close and picking the next. This works but you have to fiddle with the screen, which is less safe and causes nags.
(*) The software obviously does not use map data to look ahead. Invariably on my way into work, it wants to merge into a right lane at one point, but that lane ends in a quarter mile after two stop lights. All this does is create additional risk by merging right, then merging left in a pretty congested spot. I cancel and send a complaint to Tesla. Also on the way in to work, a single lane broadens to two lanes and I will need to make a right turn in less than half a mile from that point. FSD will not choose the right lane, and if I force it, it tries to merge into the left lane meaning it would have to merge back right away in a very congested area. Weirdly, in the first spot where I have this merge problem, FSD prefers the right lane and in the second instance, the left -- both are obviously wrong if FSD looked at Navigation data.
On my way home, it does the same thing on a different stretch of road -- about 1000' before the right lane becomes a right turn only lane, it tries to merge into that lane even though I need to go straight there, and turning right would mean a major detour and breaking the route Navigation has set.
It also handles rural stop signs badly -- these are usually 10-20' from the actual intersection, so it stops even with the sign, then creeps up to the intersection, stops again, then goes. If I have a car behind me, I take over so I'm not being a jerk.
Anyway, the singing dog comment above is spot on.