The calipers and discs I sourced are of course Audi/Brembo OEM.
When it came to the pads, I sourced some around £60 cheaper than the Audi (Pagid) ones. These were made by Lucas and 'looked' identical, so I thought they would be fine.
Firstly, they didn't quite fit, as the semi-circle which sits in the pad support bar needed rounding out with a file to get them to seat properly. But that wasn't a major issue at the time and was easily sorted.
However, although substantially better than the stock S4 setup, they have never felt 'right' and it was only when Doug (MRC) came to drive it recently that he said they felt poor, not how those brakes should preform, and he thought the pads needed changing. On inspection of the pads, there was plenty of wear left, so I decided it was time to fit the RS6 brake hoses which had been sitting in the garage for a while...
But whilst at MRC yesterday, I decided to swap the pads out for the RS4 B7 OEM ones, as the wheels were off. Some of the original pads were a bugger to get out (presumably due to the imperfect fit in the first place), some were a bit glazed and one had a quite a big 'crater', but not badly worn.
However, once bedded in and on the road, what a difference!
So that's my experience and little lesson learned - 'you get what you pay for'! (oh, and the fact that Doug is normally right first time
)