No problems with mine. I really rather like the NA version of this car. I think the suspension is better suited to handle the 160hp that the stock engine produces (EDIT: as compared to the ST's 252hp), but to each his own.
It has a wide power band, kicking in at about 2500 rpm all the way up to about 6200 rpm.
Below 2500 rpm, the engine lags significantly. Gotta drive it like you stole it.
Other than a scant few mysterious pin-hole coolant leaks on just a few cars, I haven't heard of any problems with the engines.
On the other hand, I have heard that GDI engines are bad about carbon fouling on the intake valves to the point that the engine can't suck in enough air to run/breathe (think asthma). It has to do with the fact that there is no fuel in the intake charge.
If it becomes a problem, we're all looking at a relatively simple head job somewhere between 100,000 miles and 1,000,000 miles.