I think most of us would agree that the of all the standard wheels on the GTI/D/R the Nogaros are the best looking and their predecessors on the mk6 GTD and MK5 GT TDI/Sport were also a handsome wheel (Charlestons).
The thing is with these type wheels is that the diamond cut is designed in to show off the wheel highlights and once you go for a plain finish the detail gets lost and the wheel ends up looking a bit 'heavy' (for want of a better word).
Fairly plain wheels always look better in one colour but ones with nice details like the Nogaro and Cadiz need the contrast to look their best.
To give an example lets have a look at the MAM RS2 wheel which is not so loosely based on an Audi R8 alloy style.
It's not a million miles away from the design of a Nogaro and there are lots of pics on google that show it in different styles.
When it's in a polished front with black insides it looks pretty slick, simple, elegant and uncluttered. When it's in one colour it looks a bit "awkward" and heavy.
I can't get the images to go across using the phone so i'll just link to the manufacturer website where you can see the pics but Google searches show them on cars.
http://www.mamfelgen.eu click on RS2, it'll give a vague idea of what Nogaros would look like in different finishes.
Anyway, for info, the Austins are just as bad for the marking on the black paint.
I recently put my Austins back on the car after nearly a year and a half. They had literally been on the car a couple weeks before I took them off from new and there are still chalk marks on the tyres - but even so the black is marked. I clearly remembering thinking "WTF" when I cleaned them when they came off the car with literally a couple hundred miles on them.
As an aside, after running two different styles of 8x19 wheel over the last year and a half and for a few years before that on my Mk6's I can say that the 18's are a lot more comfortable. It has surprised me the difference. They run at lower pressures which helps but boy does it make an improvement. The only downside is that there is an initial bit of 'roll' when turning quickly where with the 35 profiles on the 19's there was just very quick turn in with no flex.