I have used a Ragazzon straight through centre pipe and a Supersprint back box.
There didn't seem much to choose between the two in terms of quality of manufacture or ease of fitting.
The main surprise was the state of the original Alfa exhaust. It was a horrible rusty old mess, even though it has only done 28,000 miles.
The car is really pretty loud, particularly at tick over and low revs. It is a bit boomy at 1500-2000rpm at slow speeds, but doesn't seem to get much louder at higher revolutions.
Most of the noise is left behind you and cabin noise seems pretty bearable. It is only a little noisier than standard in the cabin at motorway speeds. Wind the window down and you can hear all hell breaking loose behind you.
The noise is fairly deep and mellow, rising to a fantastic howl when you wind it up.
It sounds great and there were no real snags with fitting it. There isn't much clearance around the back box, but it doesn't foul anything and the centre pipe is tucked up nicely out of the way.
Here's what came off.
Here's what went on.
Here's what the tip looks like.