Waze on carplay sucks IMO. I hate to sound like an ungrateful bastard, but I've been waiting for this moment for a long time. Unfortunately Apple forces Waze (and Google Maps) to strictly adhere to their own UI interpretation. So you end up missing a LOT of important information and get only the pure basics. Basically it's Apple maps UI with Waze/Google information/colors, that's it. You do regain a lot of the missing information if you keep your phone screen on, but that defeats the entire purpose of carplay doesn't it?
But it's not only the UI and lack of information, it's also the interaction. It's really difficult to scroll and you can't pinch to zoom, of course that's most likely more of an issue with hardware than the software. I have a 2016 Genesis G80 and have a pretty good screen, but it's still nowhere near what I get with an iPhone glass screen.
Lastly there is no way to either use any other carplay features without being forced to use waze on carplay. So it's all or nothing.
I came to the conclusion, rather quickly, that I was better off just leaving my phone on a car holder and using Waze right on the iPhone.