Had my GTI for 2 years and picked up my R last week.
Definitely a different drive, when the roads are damp or wet the R just sticks and goes where the GTI tramped like mad and obviously the R is much more powerful, though also a little heavier - overall they are both hot Golfs and feel very similar on the road but floor the throttle and the R just dissapears down the road, along with your licence if you are not careful.
I suggest you definitely need DCC, especially if you have it on your GTI, I find the Rs Normal setting firmer than the GTIs Normal and Race (Sport) is for perfect roads/track only. I have my 'Individual' set to Comfort (for the DCC), Sport throttle (to minimise the throttle dead travel that all new Rs seem to have) Eco sound (to kill the annoying synth sound) and Sport steering (to give the steering a bit more weight - all personal taste.
You can always use a TomTom satnav which is better than the VW units, or fit one of the approved Add on units for about £450.