Are all VW Golf GTIs very firm suspension ?

[SoyStupido]

I've owned my VW Golf for about 3 months. It's standard, it has 205/50/15" tyres on standard gti alloys, I've had new rear suspension cones/bushes(rubbers that fit atop rear struts) and recently new axle bushes. I had this done as anytime I drove over the smallest hole in the road the whole back end seemed to twitch. Having done this it is slightly better. Is it a golf thing? It "twitches" when i go over man hole covers or anything that isn't a smooth and level surface. I don't drive especially fast as the roads around my area are terrible. Are all golfs like this or is mine a lemon?