Well they are on. Love the subtle rasp now at 3000rpm. Was driving around everywhere yesterday with the windows down. Noise is only slightly louder, but just as I wanted it. Performance, well the throttle response is a little better from 2 - 3000rpm...I think.
Anyway very pleased and a doddle to fit.
I followed Dorian's excellet Tech Guide, (thanks Mate). Spot on apart from one thing I disagree with. You don't need to remove the induction pipe to get to one of the cats top botls. I just used a lond extesion with a UJ on the end. Worked a treat. I also tightened the new one up this way.