I bought my 13' FR-S in May 2012, so it was one of the very first ones. I did have an ECU failure, and the computer had to be replaced (under warranty thankfully). Still is not a %100 car, but has never left me stranded anywhere... just ran really horrible and in limp mode on the bad ECU when it was having issues.
Only issue mine has is the P3051 code for ignition coil #1...runs fine even if the code and check engine comes though, nothing like when the bad ECU started failing. My FR-S has never been completely trouble free, but there is absolutely NO other car I would want to drive! I can live with the minor issues it has.
Personally I would go for the '14.... because Asphalt
It's a sweet paint that has 5 distinct appearances based on lighting conditions....