I very almost bought a 123d, but I was put off when 2 BMW techs and a BMW partsman of 20 years mentioned that they're full of E30 parts.
You could see that as good as the parts will be cheap, but I see it as lazy development.
Back to the original topic, didn't Jonnyc go Ed30 > S3 > Ed30? There must've been something about the GTI that the S3 lacks.