I went from a 2.2D 175 sport (which had a free upgrade to Nav) in August 2015 to a 2.2D 175 Sport-Nav in Sept 2015.
Improvements:-
- LED adaptive lights instead of Xenon steering ones
- Memory Drivers seat and electric passenger seat
- The suspension tweaks have made a slight improvement in ride, IMHO
- Improved fuel economy, currently 43MPG average compared with 41 over 70K miles on old model
- Front end looks better and is a damn sight easier to clean than the hexagon design
- Reshaped wing mirrors are quieter
- I wasn't convinced about the electric parking brake initially, but am now a fan of it. Would be more so if it auto applied, like VW
The big downside to the new model (for me) is the MZD connect system. OK, it has a bigger screen and is perhaps easier to use, but why throw out a system that has inbuilt GSM for data and replace it with a system that requires a phone hot-spot? After almost a year, it still doesn't work reliably and is a right PITA to connect. Also, the map subscription promised two updates per year and it's now been 8 months since the last one and Mazda can't confirm when it will arrive...
As for oil dilution, I never had it happen on my original in 70k miles (although it did have major work on a blown turbo due to camshaft made of cheese, plus a gearbox rebuild) but have just had it happen on my new one just shy of its second service.
I don't recall even being offered a sunroof on the new one but that never bothered me anyway.
Alan