I'm not sure how it is for the 9600gt, probably about the same...but I like the coolers that expel heat out of the side of the case. Unfortunately, Arctic cooling stopped making the silencers for new cards around the time when the x1900 series was the rage. By the time thermaltake came out with a ripoff of the silencer for that kind of card, it was near the end of its life.
Same problem with my 8800GT. You can mod the card to fit the TT ND1, but I just ended up buying a silencer5 rev3 off ebay that should fit.