I only recently purchased my N810 but it hasn't had any trouble locking on to satellites within 3 minutes. To me this is an acceptable time frame for now. I will admit the unit is not EXACTLY correct with the coordinates but it is pretty darn close. I will say that the speed meter is definitely very accurate within a couple mph. Clocked me perfectly on the city street at about 35mph and then on the highway at like 68mph.

If down the road I feel the need to obtain an exact signal/readout then I will pony up the $$ for a BT receiver. Right now Im just fine with its performance.