As a navigator Waze is fine, but it seems to be missing a lot of residential addresses. Waze had a nasty habit of jumping my vehicle icon to a nearby parallel street, and while it was nice to have both 2D and 3D maps, the software seemed to change the zoom factor without me telling it to. This erratic zooming seemed to happen when I went to a menu and then returned to the map.
The maps aren't very attractive. There are both day and night views for the Waze maps, but even when set to 'auto,' the night map comes up no matter what time of day it is. The maps and POI data are all downloaded from the internet, so if you're in a "dead zone" for data, you have no navigation.
As for the social functions of the app, they are a great idea, but in reality you're only going to get information in a densely populated areas. Even then, you may not get much of anything in terms of reported incidents. If you go to the Waze web page and look at the national map for reported incidents, it is pretty lightly populated. Of course, that should get better as more and more people use Waze. A clever aspect of the app is that it keeps track of where you are while you're navigating, and uses your speed to add to its database of road conditions.
I think Waze is promising, and if you don't want to spend money on a turn-by-turn nav app, it's a start. To be really useful some of the bugs need to be fixed, the address data needs to be more complete, and there need to be a heck of a lot more people using Waze so there is more incident reporting.
This app is free and implements some creative ideas. If you're thinking about getting a nav app, but you're on the fence, make the risk-free download of Waze and see if it enhances your driving.