My sister drives the VW Golf GTi, so I think I've got enough seat time and credibility to give some insight incase you were considering purchasing one, or just to clear your general thought on the car. =)
Firstly, its everything you hear about it. It's fast, stable, very comfortable, and very contemporary. In other hatchbacks you may feel a slight uncomfortable fear when you hit its top speeds. But in the GTI, my sister, my girlfriend and myself all hit 260-280km/h on the highway and the car was just as stable as it were static. And how can I talk about the GTi without mentioning its DSG gearbox. I must say, it is a pleaure to drive with. Even today, I still drive it sometimes and cannot believe how smooth and fast the gears change. Even in auto-mode, the gears change seemlessly on its on to get the maximum amount of torque for each situation. It's almost like magic. German magic. Haha. Where comfot is concerned, the seats are highly adjustable, and theres alot of room in the back as well. And supposedly the 4-door ones are abit lighter than the 2-doors, so that's two birds with one stone. Haha.
Sorry I cant give much feedback on the other cars. I've personally driven a C230, a BMW 328i and an AUDI S4, so my various opinions for each car would be rather unnaccurate when concerning the cars you mentioned.