I've collated this example of performance to illustrate my concern. The lack of alignment of the Holux is not due to the Google photo as I've overlayed the GPX on both OS and OSM mapping on different platforms with the same result.
|Three GPS logging devices and their respective tracks along a suburban track near home. Mapping is OSM, Google Earth and OS 1:25000 respectively. Software was Garmin Connect, GPS Visualizer and Android Viewranger.
Holux binary logs record latitude and longitude as 4 byte, 32 bit floats. This should allow 7 to 9 significant figures of a decimal number which is plenty for real world logging. It is also worth seeing this illustration of truncation errors.
|5 minutes of capturing NMEA sentences followed by logging. Plotted as divergence in degrees from the average position indicted from each recording.