I personally had the same dilemma, S or SV.
I ended up choosing the SV for 3 reasons:
1. Better seat covers - I test drove an S and I hated the feel of the material, it just felt cheap.
2. Cruse Control - I drive the highways sometimes and I like to have the option to relax.
3. Price Difference - For only $2k difference, I was able to get all the features of the S + Nav, Cruse, QC, Heat Pump, LED headlights, 6KW charger, Automatic heat/AC controls, and nicer seats.
Then again, I was stepping down from a top end Altima with Leather, Nav, and all the bells and whistles. That right there made it hard to give up all the features.
But as with anything, this is only my opinion. Do what works for you.