Playing devils advocate for a moment here... although seasoned wazers such as ourselves realise this criticism of the product is a bit unfair, it's important that we take it seriously nonetheless rather than simply rubbishing it without a second thought, because if there's one person who feels sufficiently negative about Waze on the basis of a quick look to then register with the user forum just so they can tell us all how crap they think it is, then how many more potential users are we losing every day for similar sorts of reasons?
Let's be brutally honest here, Waze in its current form is NOT a genuinely viable alternative for many people to the likes of Tomtom, Garmin, Google, Nav Free etc - the mapping data is incomplete (woefully so in some areas) which isn't a good start, and the frequent server timeouts don't exactly help promote the feelings of reliability or trustworthiness that you're probably looking for in a nav aid. Even those of us who can deal with the minor flaws and are willing to put in the effort to make it better still get frustrated with it from time to time, so try putting yourself in the shoes of a complete novice who's heard about this great free nav app, decides to try it out, and is immediately faced with one or another of the things Waze does badly so much better than the competition...
I stick with Waze only because it's good enough for my needs and I know how to work around the limitations as and when required, and because I absolutely adore being able to create/edit the maps. But if I was just looking for a satnav that could direct me reliably from point to point and wasn't interested in learning why it behaved the way it did, then Waze wouldn't even be installed on my phone, because right now I don't think it does the basics well enough to compete against the paid or free alternatives, and the extra features it offers aren't sufficient on their own to compensate for these basic shortcomings.
HTC One X - Android 4.1.1 - Waze 220.127.116.11 - International Server
AM for NW London and the M4-A404-M40 loop - Editing Expert
WME enhancement scripts (WMEOD:URO:LMUR:SRS) @ userscripts.org