Think your right, the golf is much smoother and always shocks me when I do look at the speedo where the Leon did feel a bit thuggish when you gave it some so probably felt quicker to the driver.
leon was also happy to chug around the local ring road 30/40 MPh in 6th but the Golf isn't very forgiving and not happy to do this. You have to work it to get the most out of it.
Hit the right gear in the GTD at the right revs and it can all get very exciting very quickly.