Do I want to spend hours trying to figure out how to update a 10 year old device? Or would I rather spend $100-$200 on a brand new one with the latest maps?

The ideal situation would be a device that you buy once, but it's also one you could use with whatever map data sources you want (OSM, commercial, etc.) - based on an open format.

(I know GPS is also dependent on the satellites being available, but since it's government-owned and critical to many parts of the infrastructure, it's likely to stay around for the forseeable future.)