Sorry @ved789 - the tread was on RS3OC.com
There is quite a long post with pictures. The branching tube i've mentioned earlier seems to be the only noticeable difference. Just before the two pipes feed into the rear oval exit, there is a branching tube on the Sports exhaust which isnt present on the standard one. There may be more differences and/or software changes too.
From memory of the other post, the sports exhaust is ~£1600 to retrofit!
Here are some pics I took today when on the ramp of the sports exhaust, if you want higher res ones let me know:Anyone know the actual physical/mechanical differences between the sports and standard exhaust?