Have had H-pipe fitted, and my god - the sound when accelerating is truly exceptional! I was trying to think what it reminds of, and I've come up with perhaps similar to a nascar sound, or perhaps like the dubbed sound they used for Bullitt's Mustang, or possibly even like a Maserati from the 50s or 60s (I need to check on youtube how a 250F sounds).
Anyway, simply stunning sound. Only thing is for me it is possibly a little too much around town. I felt far more conspicuous when I restarted and drove out of the petrol station. I'm sure I'll get used to it though....but on the open road it really is epic!
Oh and Mark re a video, well with the best part being the hard acceleration which I can't video. On tick over it doesn't give any indication of the driving sound. It has to be experienced in the flesh I'm afraid!