It's not that it's much stiffer, it just cuts motion more quickly, much more controlled of a ride, especially at freeway speeds.
As to around town, it's indeed a slight bit more busy, but not objectionably so. If you want additional control of body roll and to aid high speed stability, then go HD. If these are not a priority, but ride quality is, go comfort-a new set hardly makes for a wallowy ride.
"If everything seems under control, you're simply not going fast enough" --Mario Andretti
1995 E500 street car
1986 Porsche 944 Turbo S track car