Yeah, the quality of the tyres do make a difference, and in general terms of tyre construction, directional tyres were supposed to be better than non-directional/symetrical tyres for reducing road noise.
Another issue is the quality of the road surface too. On certain sections of the A1(M) and the A11 (I think!) which have concrete as the road surface, the road noise dives me potty!
Anyhow, in the RS, it seems happy cruising at 140 to 150 leptons - which is roughly double zutons, and about half whiptons per hour!
