Better Than EDGE
Certainly, the performance was significantly faster than the EDGE network-based iPhone. Loading a variety of Web sites and even browsing YouTube can be done in a reasonable amount of time, whereas using EDGE meant pages loaded at a painful crawl. Even checking e-mail over EDGE seemed agonizingly slow. Truly, given the Internet features of the iPhone, this is the performance the first model should have had. For me, the faster download speeds are well worth the price of upgrading as well as the extra $10 a month for 3G data service that is required in the iPhone 3G plans.
The second major addition is built-in GPS capability. Although the original iPhone can approximate your location by triangulating between available cell phone towers and known Wi-Fi hot spots, its effectiveness in this regard varies widely depending on where you are: It could be within 10 or 20 feet in one spot and off by a mile or two just a short drive away. The iPhone 3G's GPS technology could pinpoint my location to within less than five feet in almost any location I tried. And despite some concerns among veteran GPS users that the iPhone might take a long time to acquire GPS signals and calculate a position, I found it could do so within a minute on each try.
That said, some structures (like the 150-year-old brick brownstone in which I live) can impede the iPhone's ability to reliably acquire GPS signals. If that happens, the iPhone 3G will fall back on the triangulation method. To clue you in on which method is being used, the images displayed in the Maps application will vary. Real GPS locations are displayed as 3-D blue dots; locations based on the less precise method are shown with the same two dimensional blue circles used on older iPhones.
GPS capability is also fully real-time, so you can monitor your progress on a map or satellite image view (or a hybrid view) as you move (either on foot or by car) from place to place. The feature also integrates well with Google Maps when you use that application to find directions. I should note that the Maps application also integrates well with other address-sensitive features on the iPhone (either model) such as contact addresses or the search feature. While turn-by-turn navigation isn't yet available on the iPhone 3G, the combination of GPS and Maps is a fully usable alternative. Move over Garmin.
I also can't help pointing out the cool factor -- or, depending on your point of view, the scary, big-brother factor -- of using the GPS capabilities with a satellite view or hybrid map view. With the availability of discernible images of objects as small as cars and trash cans, just walking around the neighborhood -- while looking at the Maps application and watching it zoom and re-center as I entered addresses or requested my current location -- offered a distinct spy/sci-fi movie feeling. I'm just not sure if it's closer to James Bond or Minority Report.
One of the real advantages of built-in GPS support is that any iPhone developer can now use the iPhone 3G's location services. Several free applications currently available through the App Store already use this feature, including the LoopT social networking app and Near Pics, which displays photos of landmarks near wherever you happen to be. As more developers find innovative ways to offer location-based services, the GPS advantages will only grow.