I personally tested navigation systems by manufacturer on YouTube...

A certain channel was
testing Kia Built-in Nav,
TMAP,
KakaoNavi,
and NaverNavi...
And it turns out Kia Built-in Nav was the fastest..
I wondered if it could really be that fast,
so I selected a destination using the built-in Kia nav in my own car
and compared it with TMAP and KakaoNavi.
Kia Nav: Arrives at 18:03,
TMAP: Arrives at 18:50,
Kakao: Arrives at 18:40.
When I drove following exactly what the Kia Nav told me,
I actually arrived around 18:05...
It gives directions incredibly fast,
but it's almost like it's being sneaky with the routes.
If there's a long line, it tells you to detour through alleys to overtake,
or it takes you through routes where you'd think, "Was there even a road like this?"
and you end up thinking, "Oh, this road connects like this..?"
It guides you through those kinds of paths.
I think it might be time to say goodbye to TMAP. haha