ive had both and no it does not feel slower, even official figures are 0-62mph are 6.8secs edition 30 and 6.9secs mk6 gti, mk6 is also a little bit lighter, mk6 gti is certainly more nippy at lower revs as is standard mk5 gti over ed30 but mk6 gti does not run out of breath when it gets to around 5200rpm which is were ed30 is better than standard mk5 gti imo.