Can't comment on PS4, but PS4S are very noticeably quieter than Conti 5Ps so if Conti 6 are the same as 5Ps in the noise stakes, then they will be noisier than PS4S.
I had Conti 5 on my Mk7, and think the Conti 6 is quiter.
But as i said, maybe the PS4S is better.. 
. I buy them next time if it´s the way.. 
If the Conti 6's are quieter then they'll likely be on a par noise wise with the PS4S. 
Think all the tires in this size are noisy . But you are satisfied with the performace of the PS4S?..
Wide, yes, to degree 19's can be noisy but some are moreso than others. Same with the hardness of the ride.
I've only had the PS4S on since Friday but have done a fair few miles now on varying roads to test them out, and they are so far proving to be superior to the Conti 5Ps on all levels, and that's saying something because I rate 5Ps highly. The PS4S are - quieter, less harsh and more comfortable ride even with DCC in Sport, better at absorbing rough/potholed roads, better grip, exemplary braking. They've yet to be driven in the wet and it will be exciting to see how they fare through winter (do not use winter tyres in my location). More extensive thoughts on the PS4S (so far) in my thread here.
http://www.golfgtiforum.co.uk/index.php?topic=275792.msg2572744#msg2572744Tramping, as discussed above is not an issue on the 4WD R, as is more prevalent on front wheel drive cars and a poor tyre can really exacerbate the issue.
I know a few with Conti 6 on their R's and they are very pleased with them.
