I have never rode the 2, but have the 4s now. I absolutely love them. I got them put on at the beginning of this 'riding season' and have put almost 10,000 miles on and they have performed flawlessly in all conditions. They are showing minimal wear. The ride is very smooth, but provides great feedback and they are confidence inspiring in the curves. I ride in the rain very frequently and have never had them get away.
They have done many hours on interstate and have been at very high speeds. They have taken me through some very aggressive twisties. I've gotten 100% of the rear rubber on the pavement. My most recent trip was to the tail of the dragon and cherohala skyway where it rained almost the while time. I pushed these tires pretty hard there in the rain with no problems the whole time.
This isn't even the lowest I got; just the best shot the photographers took for the day.