People are only going to recommend what they chose. Robin will say Milltek and Mat will shout for Blueflame
Your not goig to go wrong with either to be honest. The Milltek has a more grown up sound in my opinion understated but there when you want it, were as the Blueflame is a bit thuggish most of the time. Quality wise not much between them and the `Milltek drones more than the Blueflame.
Thats about it, oh the zorst is the same for both the ED30 and the GTI both 3in pipe now.