I have tried Waze. I was a fairly early adopter and used it more as it was gradually being developed. I put in a fair bit of work to get the maps accurate near where I lived a few years ago. I rarely use it these days though but still have it installed and occasionally fire it up.
Waze has enormous potential, I think. It's current limitation is number of users, which is where it gets most of the traffic info from. Ultimately the problem for me was at any one time I could see maybe another 2-10 users in the same city as me. That doesn't give a big pool for live traffic. I saw it evolve and the routing improved massively as it gathered data but it was very rare that it would actually warn me about traffic.
Currently Waze's potential is also limited by Google refraining from throwing all thier traffic data at it. I think they are basically trying to avoid legal challenges on Anti-trust from the likes of Tomtom. The traffic info is based on croudsourced 'floating car data'. Tomtom, Google, and Inrix all have massive data pools that nobody else can touch at the moment.
I've never been that bothered about speed cameras, as I usually don't go over the limit. Waze is as good as the user pool in your area. If you've got regular users that share the camera locations, it's great. Unlike most apps the camera data is free - a big bonus.
Ultimately, Waze doesn't currently do what I want it to (reliably detect traffic and offer faster routes around it) in my area. I'll keep an eye on it. Ultimately I have no real brand loyalty. I have Google Nav, Waze, Route 66, Tomtom and Navigon all installed on my phone. In the past I've used Sygic, M8, Navfree, Wisepilot etc. I just use whatever does the job.
Actually, I'm encouraged by this rerouting issue with Google. I think partly, the traffic data is geared more for mapping info and less for navigation. Tomtom's traffic info has been geared for navigation from the off. Google will learn lessons and make it better. Competition is good, so long as nobody ends up with a monopoly. That's when innovation can stop.
Ultimately 'traffic' is not just traffic. I would not advise anyone to pay for traffic on Navigon or Co-Pilot because what Google provide for free is better. I also wouldn't advise paying for traffic in Sygic - they use the same data as Tomtom but the implementation is crap. To use an anlaogoy - Navigon and Co-Pilot do a road atlas level of detail for traffic. Google do perhaps a 1:25000 OS Map level of detail. Tomtom (incluing Route 66) do A-Z level of detail. The products are perhaps the same category but not the same type.