not sure why you think this? You still have to have some state (you cannot just rehydrate state of file system upon restart and keep everything in mem). To rephrase, those who don’t understand databases are bound to reimplement them…poorly. Why you think upgrade of metadata schema in those files will be less of an issue on upgrades (surely this will happen, file format will change, just now without constraints, foreign keys, checks and with manual reindexing and manual query optimizations)?

If you are looking to get data on your route (speed, distance), regular gps will do, errors are not high, as these error cancel each other usually. If you plan mapping for OSM - also really not worth it, as OSM is generally not more precise than 2-5m. I have dual-frequency phone and I am not impressed (accuracy is bit better, but I didn’t have wow effect). If I choose again, I would optimize my purchase for battery life (far more important in nature:D)