I fitted one the same day I removed my JF box to send back ( returned due to poor power delivery, jerky when going slow) although very powerful when your foot was down. So I was expecting big things, but it felt no different that stock and certainly slower than the JF box. Andrew did say the JF box could have been over boosting so gave uneven comparison to a proper tuning box, which is why it was so poor the rest of the time. After cycling through the maps, I gave up and gave it back to DTUK after a week. Since then I have had a full remap on the GTI by Revo, which was awesome!
That was the past and now have my R and searching for a tuning box because the new 15 plate ECUs can't be unlocked yet so can't get s revo or custom map done.