No, that spell is oftentimes unreliable. I was trying to do the White Phial Quest once, and it sent me on a looping path that ended up point back towards town.
Another time I was trying to find the most direct route to Riften, and it pointed me to Kynesgrove. I still followed it, just to see where it would go, and once I got passed the town, it pointed back towards it. Turn around and it goes back in the other direction.