I bought mine new and only a few months ago so I cannot speak up for a year old car. The few minor problems Ive had though wouldnt suggest any issues. in fact you may even get a car with any minor initial faults sorted out.
As for the car itself though you really want one!! Ive just started to give it some welly (used to it and worn in) and what ever you want out of it its there. i have to drive through the city every day which it copes with beautifully. Evenings and weekends its off to play golf so lots of country roads
I prefer the 156 over the 147 (styling, size etc). And dont worry about styling updates the GTA looks so good that it still looks like a new design.
DO IT!!!!