I personally not fond of Conti due to CC5. I am using Triplemax. Good all around tires, stronger sidewalls and better handling for average family cars.
Im not sure if Conti change better quality since the 6 series was newly introduced. End of the day, just see how much it cost, whatever is on sale just change to that.

But what to do the quietness is something unbeatable at their price. Anyway for my 15" rims n a budget of RM210. I rather pay for a Triplemax.