I just got mine installed over the weekend and drove around for about 4 hours with it...
My routing was really good...
I was pleasantly surprised at how quickly and accurately it re-routes if you make a wrong turn...
I took some routes from my home where I could take about three VERY different ways home(interstate, highway and back roads)...
It first took me the interstate... I went the highway... It re-routed in about 5 seconds... I then got off the highway and took some back roads... Again, it re-routed in about 5 seconds and was spot on...
In one instance I was taking a highway and I could turn either NORTH or SOUTH to go home... It wanted me to turn NORTH... So, I turned SOUTH...
It actually prompted me to make a u-turn where the divided highway merged... I was surprised by this... First that it knew exactly where the divided highway merged and second that it wanted me to make a u-turn...
But, once I passed that point and kept going it then re-routed me the SOUTHERN route instead of trying to get me back to the NORTHERN route...
Long story short, I am very pleased with its routing capabilities and its re-routing capabilities...
One thing... I know there is a setting for giving priority to SHORTEST route and QUICKEST route... I know this is based on average road speed...
So, you might try switching between the two...
Good luck,
Mark