Just one more note: I use a GPS 76S while roving. It displays the actual maidenhead down to the second subsquare. That is VERY useful while I am driving as I know exactly which grid I am in.
I also use the GPS clock to sync my Windows computer when I don't have internet access (which is rare now days; I use Verizon USB modem). I open my clock and set it to the upcoming minute. I then press "apply" about 3 seconds before the minute. That gets me close. I guess there is a lag time in there.
HF, 6m, 2m, 70cm