The GPS receiver in the Nokia N810 isn’t very strong. I have yet to get a position fix indoors or even in a car. Outdoors it does acquire position fixes, but there is a fair amount of uncertainty/jitter. Standing still my “position” wanders about. It is good enough to figure out which block in a city your are on and even which end if it isn’t a tiny block. The maps in the database are low resolution, i.e., line segments, not smooth curves. The Points of Interest (POI) are sometimes out of date (e.g., restaurants that have closed). Only roads are included, no footpaths, so not very useful for hiking with the included maps. (Is there a source somewhere for the USGS topographic maps?)