Before you make that final decision, there must be a Golf demonstrator out there for sale that's close to the spec you wanted? Ask Eurocanterbury (where i bought my Scirrocco and were very helpful) to call around the country and find you a car close to your order? There are hundreds of dealers and therefore hundreds of demos out there.
I wouldn't worry about buying a demo, my Scirocco was a demo and it was fine, plus how long are you going to keep it for, a few years? Plus if you're looking at BMW demo cars then you're obviously open to that option.
I had a 3 series, lovely car but the Golf has more usable room, better handling etc.
Just a thought?