Noper, at least I doubt it. It's all about what GPS satellites have view of you. Sometimes it gets SO close to where I am, other times its quite off... Been pretty dead on for me tho...
I can honestly say I use to feel this way about GPS... some days it was on and others it was WAY OFF!! I read a post from someone else to also turn ur wifi on and it helps... so I did and it makes a huge difference.. its actually reliable if u turn on wifi also.
If you're not dead on then its not getting a sat lock but it's either using cell tower triangulation or the location of the wifi hotspot to determine your location. Also, as mentioned several times on this forum already, sometimes it's a network quirk with Verizon or the gps in the phone. For the latter 2, restarting the phone or turning airplane mode on then off seem to help usually.