Hi mate
In my experience from owning both an 8v and a 16v the later does use considrably more oil. I asked my vw specialist about it and he said they just do, so check the oil more frequently. Mine is also "tappetty when cold for the first few minutes, but again my guru says the car is mechanically sound. Check the colour of the emmission, if it is slightly blue that means you are burning oil. Check the sparkies for oil aswell. If they have oil on them then you could have problems but should be fixable.