I've been using Google Maps on the Nokia E71 for a few days now and couldn't be happier. It runs much faster and smother than Nokia Maps, although it uses data which might not be ideal for some people. If you have an unlimited data plan like myself than it doesn't matter.
Google Maps uses GPS and your phones signal to get your location. Upon starting the application your location is found almost instantly. If your on the freeway, you can check the traffic by pressing 7. You'll see either red, yellow, or green. I'm sure you know what the colors stand for.
Zooming in and out is a breeze by pressing the 1 and 3 key. You can scroll around the maps and then push 0 to get back to your current location. Keep in mind that you right now you have to press the shift key at the same time when using those shortcuts. I don't think Google recognizes the E71 as a qwerty phone with their latest version. Probably because the E71 is brand new. I'm hoping in the future you won't have to hold the shift key + shortcut to use these tools. It's really not good when your trying to drive and get directions (which I don't recommend).
If you need to search for something near you or get directions you are using the most powerful search engine in the world. Typing "gas station" gets you all the stations nearest to your location. Pick the one you and you you have tons of options. You can call directly from the application, go to website, get directions to and from the selection, and below that you are presented with the rest of the search results. You also have the option to "save to contacts" which is a huge plus for certain businesses or contacts that your always in touch with.
Google Maps can also find your location buy using your phones signal. It's hard getting a GPS lock in some buildings and the phone's signal is an approximate location, usually within about 1200 meters. Handy if your sitting at the DMV and decide your gonna try and find a place to eat. You don't need your exact location, but the general location would be perfect. Satellite views are also available.As for directions, you get step by step instructions. You go to the next step by pressing 6 and back by pressing 4. It doesn't update turn by turn. There is no option for voice guidance, but hopefully Google implements these features in the future.
To download Google Maps, go to http://www.google.com/ on your E71 and scroll down to where it says Gmail, Maps, and more. Click the Maps link.