I have been using this car for 20,000 km. I have bought it new, a base model, no ABS / EBD, just prior to the Opel release of their TwinPort engine version. The more electronics you've got on, the most likely something will go wrong.
I assumed that their current model would be a ripe debugged mechanical design; since their 16V 1.4 engine motor had been in the market for almost 6 years. To this point I have had no mechanical problems. The engine efficiency is quite good. I am ordinarily getting 6,5 lit / 100km.
Performance for the 1.4 90hp engine? The car weighs 1.100 kg; It is rather heavy for this engine. The previous model scored much better in acceleration, because it was lighter.
Road grip is very much improved compared to the previous model. High speed cruising is quite stable too.
Comfort? Look to french rivals for that. The seats are stiff and uncomfortable. Noise? Rough and felt over 4.000 rpm; with 5th gear that is 135 km/hr, bellow that it is OK; I can live with that.
Service cost? Service intervals are every 30,000 km, double to the previous model. Generally speaking, opels are rather expensive to maintain in Greece.
It is quite roomy for its size. I had a very consciencious decision among cars like Honda Jazz, VW Polo, Ford Fiesta, Daihatsu YRV and Fiat Punto and this model. It was a compromise between value for money, performance, room, and previous owner experience with the Opel brand.
On the whole, if the car maintains its reliability, I would consider it a decent purchase, worth the 12,400 Euro I shelled for it.