I think you mean PND - Personal Navigation Device.

GPS is a geolocation technology and has nothing to do with maps or routing.

However, what do you mean by a "real" [PND]? A PND would be any device that provides for geolocation, some map support, routing, and geo-search. This could mean a lot of things depending on quality and level of implementation.

The built-in Maps application, in my opinion, is just embarrasing. MaemoMapper should have been included by default - as it is better implemented, fuller featured, and abides by the current goals of Maemo in being open-source and having a community. It also utilizes free and open map sources (OpenStreetMap) instead of requiring inane, and ill-working, map downloads in the hundreds of megabytes.