Installed today!
Install took 6 hours, YES 6 HOURS!! Mechanics were working between mine and an Audio TT with a boost leak, a long day but very interesting.
First off was to remove 2 heat shields that surround the manifold and cat converter. The last bolt which also holds the lambda sensor (I never managed to get in and see this bolt, this was mechanics description) had to be removed from above. This mean removing the tray at the bottom of the windscreen and the wiper motors.
Once the heat shields were removed (they took hours due to Scottish climates rusting/seizing EVERY bolt) the pivot mount/dog bone mount/rear engine mount or whatever you like to call it was removed so the engine/gear box could be pivoted out of the way of the GINORMOUS cat thats attached to the manifold. Once this was off it was plain sailing.
New Hot-Pipes manifold is a beaut, fits beautifully and looks stunning on the car, it's a shame nobody will get to see it! Only bad point is the gasket that was supplied. It was cardboard with a metaly plasticy outer layer that was peeling off. I re-used the stock gasket as it was still in good condition and is all metal.
To make things little easier the exhaust was taken off its mounts and slid back a couple of centimetres to create a little more room at the manifold.
For the lambda I kept the bung where the 2nd probe should go and cable tied it (the 2nd probe) to outside of the manifold so not to flag a fault code. (not onto the manifold obviously)
Power increase? Hard to tell as the roads are so slippery and greasy today I could barely push it on the twisties that take me home. Will get it on the motorway and try a couple of 2nd and 3rd gear pulls.
Noise - I now have manifold, straight pipe then muffler. It's crazy loud above 3500-4000 rpm, raspy but I love it. Below that its not too bad, extremely tolerable for daily use. Cant wait to go a couple of tunnel runs over the weekend
The manifold seems great value for money, I wont be dyno'ing my car to prove results as I don't have access to a Dyno. I know my car very well as I drive high mileage, hopefully i'll see a noticeable difference when I get a good run with it on

today at 30mph flooring it in 2nd resulted in a lot of noise and even more wheel spin. Not ideal!