I am missing something here -- a GPS from Costco (Garmin) does not require a DVD update, and why does my technologically advanced 2010 TL need one? Other than hooking you for yearly subscription, is there a reason why? Can someone explain the technology difference between the two?

 

Generally all GPS units are updateable, Garmin comes loaded with "base" maps or comes preloaded with detail maps. About once a year they also offer updates to the "detail" maps with new POIs, updated road detail or new areas included. They also offer a "lifetime update" service for a fee(I dont remember what it costs).
New Acuras have a HDD, older Garmins used to have an DVD that loaded to the internal memory or a memory card and Honda motorcycles have a memory card.
Prior to 2009 the Acuras used a DVD in the trunk unit that was replaced when updating, and now the 2009> use a HDD that copies the DVD to the drive. If you feel that you need the new POIs or newer detail, then the update is useful to you. I think that most companies use information from a company called Navtech that supplies the road information.

NYPete