Looking at the pics, it looks like mine was cut closer to the flexy as I have a slight bend in my decat pipe which resulted in a bit with a diameter a little less than 3" at that point, but the noise with non silenced centre section is louder on boost.
Spool is quicker, and the car appears to be more lively across the revs. Bum dyno not too accurate due to weather, but I believe the car is a little quicker now than it was before.