Yes it would be far more accurate. But where has this already been implemented like this dns has been already with logging, email alerts, and name server update. I have not see a free GPS app that works cross all GPS devices and can provide this useful info.
Also to an earlier post. There are many tools you can use to trace IP address to locations. VisualRoute, the link provided above, and local/county/federal governments (if your car is stolen) can assist you with. On the otherhand, my dad works for the department of defense and can get cable/dsl providers to provide IP address to house locations within minutes.
There are some flaws but as an extra layer of protection that sits quietly in you system tray, I think it is worth the effort.
I think with GPS reporting your location every few minutes, and this tool as another option is great protection. If you car doesn't have line of sight visual to a satellte and you cant use GPS obviously if you are in a garage for example. But if someone who stole your car (and is in a garage for example) who knows you could catch a nice 802.11b or 802.11n signal indoors, or from neighbors etc.
Bottom line, using a GPS reporting app and this app, covers as many bases at once.