I have a white Edition 30 and my wife has a white Polo GTI which I drive nearly every day as she doesn't use it for work and in our tandem garage the Polo is in front of my Ed30, so it's first out!
The Polo is an excellent car in every way and I really enjoy driving it, but when push comes to shove, I still prefer my Ed30. For me, the Polo has a small car feel in comparison with the Golf (seats, interior and feel out on the road) and I do prefer the Ed30 engine. The Ed30 feels more grown up and the engine feels/sounds less stressed when driven hard. If we had to reduce back down to one car, the Ed30 would win for me, but not by much.
It will be interesting to read other people's responses to your question.