I read a while back that the SPOT locater was changing the unit to update the unit and/or the communications. Is this true or am I just dreaming? Is there a new unit or is it still the same as it has always been? I am really confused because I see reviews which say the unit is barely operational and others who say it works 90% of the time. My impression was that it was working on a cellphone network but now the information says satellite signal. If it works only on a cellphone signal I might as well just use the cellphone.