Yes the 4wd system is the same haldex driven equipment as the S3, its more like 90/10 until it needs it though with a maximum of 50/50, and that isn't switched when traction is lost it kicks in when it senses a rotational difference of as little as 0.15 revolutions between front/rear which can occur on bends/corners when the front wheels still have full traction. Only the longitudinally engine mounted 4wd cars such as the passat 4mo and A4 quattro use a torsen differential based 4wd system which gives different handling characteristics. However there are only very limited details of the 'R' version of the mk6 golf. It will most likely share the same 265ps engine as the S3 but as yet I've seen NO concrete evidence to suggest it will be 4wd. Also the DSG version will probably be the new 7 speed version rather than the one you're used to.
To be honest I'm very much in the same boat as you, if neither the range topping Golf or Scirocco live up to my expectations I'll be visiting Audi. For your info the sportback S3 is available with DSG.
