I wouldn't say the clutch and flywheel are common problems at all. I've not heard anyone say that before. Sure, a clutch is a wear and tear part but premature failure is not really an issue.

Most ST170 issues revolve around dodgy idle and acceleration problems which can have a few causes. I wouldn't say it's as reliable as a normal 2 litre focus but it's a more complicated engine so to be expected really. The major parts are very strong, certainly well up to coping with lots of power.

The other parts that can niggle are replacing bushes quite often but they're cheap and you get used to it.