Q: I just bought a 2006 STS V8 and it has no disc(s) at all for Nav case is in glove box but empty). If I want the latest West only disc(s), what do I need to get? Do I need a base/firmware disc AND West disc or ??? I will buy East too if needed but I won't ever have this car East of Vegas/SLC. I see the list of part numbers above but still a little unclear as to what I do/don't need (remember, I have NO disc(s) at this time).
I believe a couple of posts back there is information outlining how to tell if your radio has had the firmware upgrade or not (you can tell by looking at how the screen menus are setup). If yes, it really doesn't matter which disc you buy. For two-disc sets you'll want the west disc but later, single disc releases everything is on one. In two-disc sets, both will have all the maps but only points of interest in either the east or west US. If you're not looking for restaurants, museums, etc this doesn't matter. If your radio has not had the upgrade you'll need to see your dealer or live with an older version of the disc. Again, the cutoff was mentioned earlier in the thread as to when you must have the upgrade for newer discs to work.
It seems that a West disc is required, but I'm not sure that I'd call an address a POI as much as a separate look-up table. I believe a lot of the information is there but not searchable. I inserted an East disc and the system limited my search areas. I did however enter a telephone number for a business in Spokane Valley, Washington and it located the address on the map and calculated a route despite being on the wrong side of the US for the map disc in my system.
Maybe I explained it poorly. I know when touring the country, I find the need to change regions and less often, DVD's, in order to benefit from full feature/function of the Nav system. It has many critics but I find it easy enough to use. When comparing it to the aftermarket add-on's, their biggest advantages are the free (or nearly so) updates and no need to set a destination to automatically get real-time detailed local services.
The OEM Nav's biggest advantages are that big screen and the HUD integration that eliminate the need for another annoying computer-voice.