To be honest mate inside the car it doesn't sound any different at all, the turbo seems to spin up quicker and seems slightly more responsive ( although I've still got to get round to changing my diverter valve this week, so ) and mpg has gone up, the sound is better when the car is being driven past you, there isn't a massive difference but its subtle.
For a mod that is free I'd recommend it if your doing it yourself , exhaust hadn't been touched for ten years so I had to cut the brackets off on the coupling as they were rusted solid but got a couple of 63mm clamps from Halfords for £1.69 each.
I watched a few vids and read a few forum post saying it can be done in about an hour an half but i'd allow double that as the bolts on the downpipe are awkward to get to and I was doing it on axle stands on my driveway and not on a lift like on most videos
