CPO 2013 or 2014 recommendation?

Hello all, I'm in the process of looking for a new-to-me CPO 535xi. Is there any mechanical reason to select the '13 over the '14 or visa-verse?

Other than the obvious 'newer' product, I'm hoping to find out if one is considered a better model year than the other. Or if there are any known issues with either year.

Whatever I buy will have less than 15k mi.



Thanks

CPO 2013 or 2014 recommendation?