I did try the VW Nav with CarNet traffic when I got my Mk7.5. I'd been moaning about the lack of VW traffic data all the time I had my Mk7 (where it was advertised as available, but not in the UK!).
The data was OK, the ability for it to navigate around problems was appalling though.
In my book, if you want to avoid traffic jams, use Google Maps. If you want to know about speed cameras, speed limits and other road hazards, use Waze.
TBH though all of them are likely to send you bizarre routes under certain conditions and I tend to only ask for directions when I get to towns and cities - I can usually find most urban areas all over the country without being told!