Did I read it right?
The R32 driver just changed his rear ARB to a fat one to try and counter understeer?
I hear what the guys is saying, in that a sh!t driver is a sh!t driver and no amount of mod's will make them a better driver, but I would say if you're doing these mod's you need to do them as a rounded package.
I've upgraded all the ARB's and springs on my car to H&R. It offers lower centre of gravity, reduced role and has reduced understeer (without making the tail unstable - in fact if anything it feels more stable).
The initial bump control on the suspension is also better than standard.
At Castle Combe, I was having a good run with another S3 that appeared to be on standard suspension. Both cars appeared top be mapped as straight line performance was very similar, but in the corners, especially the faster fourth gear one's I would make ground every time by holding a tighter line, carrying a bit more speed and getting my power down earlier.
I could see where he was losing time.
Now maybe that had nothing to do with the suspension mod's, maybe it was just the driver.... but I doubt that as it was only my second track day!
The link is an interesting read mind, but it sounded more like he was promoting his coaching abilities than anythng else IMHO.