Is GPS navigation accurate?

Yes! The GPS accuracy is up to +/- 3 meters with the new High Sensitivity GPS IC. However, the accuracy can go even +/- 1 meter with special military equipment. However, it all depends on how many satellite in view during that particular time. regards, aerobrain

yes it is very accurate especially the ones with sirf ii chipsets.. you can see in the display the accuracy whether +/- 2 meters and so on.. the more satellite in view the more accurate you can get.. it depends on whether there is a clear sky before you have a clear fix.. i am mostly using a garmin gps receivers and i find it very good compared to my ipaq which is agps-assisted..

Yes it's very accurate. The more expensive units generally have better electronic sensors and therefore they are both more accurate and acquire the signal faster. If you lose signal it will be regained just as quick as you are in a clear area again. For example, I sometimes lose a signal with my GPS when I'm out riding my mule in the mountains. When I get into an area where the trees aren't so bad the signal comes right back. I want to buy a better one so it's more sensitive and won't lose the signal as easily.