I have had my 2014 Passat TDI for over 3 years now. It is an amazing car, both on the highway and in the city.
It has got lots of torque for quick starts and merging in the city, it has a good turning radius, despite being a large car so it is great for parking. It will cruise comfortably on the highway all day.
The interior is spacious and comfortable. Controls are well laid out and easy to use, climate control and heater / defroster / heated seats are awesome.
The best part is the fuel mileage and range. Mileage will vary of course based on how you drive, speed, acceleration and where you drive, city vs highway. Highway mileage ranges from 4.3 l/100 to 5.2 l /100. City is 6.7 to 8. On the highway if I don't drive too fast, I have gotten over 1400km per tank. With normal mixed driving, 1000 km is easy and even city driving in the winter with cold starts and idling etc 800+ is normal.
There are a few things that could be improved: The entertainment and navigation system can be slow responding i.e. start up can vary from a few seconds to a couple of minutes. Since it is linked to the back up camera for the display, this can be frustrating. Usually it is pretty good, but occasionally if is very slow. Apparently there is a recall coming on that according to the dealer. The other thing is don't bother with the navigation system option. Google maps is much better and the pre-loaded maps haven't been updated since 2012. VW still has no updates available!