VCDS is worth its weight in gold if you're a regular VAG group car owner. I've had my lead since I was 18, its come in useful time and time again. Nothing comes close to it bar main dealer equipment. At work we've got various diagnostic tools which cover most makes/models - my favourite being the MaxiDas DS708, but for VAG group cars, VCDS is always better, easier, quicker.. you name it.
It'll do most coding, basic settings, adaption etc (not just diagnostics) on near all VAG control units.. the same as main dealer kit.