"That it's essentially non-upgradeable? Still true (the map updates are only map updates, there's no new core functionality). "
MyGig with nav, for example, has fairly regular firmware and map updates. Plus it does a whole lot more than just nav. The firmware updates have added and removed features over time.
Sure, you have to pay for the map updates, but that's true of the portables as well.
If you like portables, fine, but the built in systems are excellent now, imo, even if more expensive.
List of the firmware updates to MyGig with nav that you can install yourself, a map update was released in July 2008. Harman Becker is doing a pretty good job of keeping up with the MyGig firmware updates. There have also been several Gracenotes updates released.
The firmware and Gracenotes updates are available online for free. Unfortunately, you still have to go to Navteq for the map updates, but that is the case for everyone.
All of the updates involve nothing more than inserting a CD or DVD and waiting.
January 2007
Application version: NTG4_9.041
July 2007
Application version: NTG4_9.556
October 2007
Application version: NTG4_9.561
January 2008
Application version: NTG4_9.665
February 2008
Application version: NTG4_9.668
April 2008
Application version: NTG4_9.713
May 2008
Application version: NTG4_9.715
August 2008
Application version: NTG4_9.807
(2009 factory models come with software version listed as 1.055. This is similar to, but older than 9.807)