I got the Navigator Turn By Turn trial today and I can’t say that I am very impressed how the software works with my setup. First of all the program takes incredible amount if resources (Cpu and RAM) so it is slow as hell on my system.
The copilot voice is great but it is too slow. It tells you to turn left 10 seconds after you were supposed to turn left so you can’t really trust what the software tells you to do. Then you would miss all the turns

.
The software updates too slow, when you drive in a street the software shows that you are 100-200 meters behind on what you actually are, but when you slow down or stop the software “catches” up with you again.
If you do take the wrong turn the software tries to recalculate a new route, but it takes 3-4 minutes before it does so and when you are off the original route the voice stops so you have to follow the arrows and directions on the screen instead.
I am using the USB GPS mouse and I have good “signal” to 5-6 satellites when I am driving around.
512 MB RAM, 1 GHz on MII 10000 motherboard on a fresh install of Windows XP PRO.
Sorry for my bad English