Not really mate, it wasnt on the road long enough to get any
On the cat note i was literally just on the phone to George from Venom Exhaust Works discussing it, i was about to link him to the thread and you bumped it up and made it easy to find
The R34 cats are not complete yet so we discussed it and due to the short time i have to get everything ready he is going to send me a universal 500 series cat and flanges and ill get it welded up to speed up the process, he has been really helpful so if you want a cat for your car give him a buzz on 0402 753 146
Am hoping it will help with response, cant see it changing the sounds too much though as the big rear muffler should still be doing its job
Edit - Just saw you have a 100 cell in your sig.........