My personal experience of the Ed 30 i bought in the summer has been excellent.
As you may or may not know, the Edition 30 has an extra 30bhp, from the larger k04 turbo charger, whereas the normal gti has a smaller k03. The engine differs in other ways, but i am unsure what exactly

( the same engine is used in the Audi S3 and the Leon Cupra)
The edition 30 also has a larger front splitter, colour coded side skirts and a different rear bumper which is also the same colour as the car, instead of the disgracefull standard Gti rear bumper. Also it has the BBS pescara alloys

It makes a
huge difference when you see them. It has alot more presence on the road.
Half leather, and half cloth heated seats come as standard in the Ed 30.
They are limited in production also, (
allegedly only 2500 we're produced), so expect higher residules when it comes to resale. But of course, also higher purchasing prices.
On a motorway run I regularly see approx 34 mpg, when crusing at about
80 70

, but if you put my foot down you wont see much higher than 15mpg when you look at the trip computer when your home.

Performance wise, it'll give alot of cars a run for their money, (especially normal gti's

), and if you went down the modifying route, a simple remap will see it in the region of 280-300bhp, whereas the normal gti will only see about 240bhp max.
The big service you have to look out for is at 40,000 miles or 4 years, and will cost about £600 - £800 if you have the DSG gearbox too. It includes the cambelt and water pump, all filters, and gearbox oil (if DSG), I think that is all. So i'd advise to look for one that has had it already done.
I apologise for the messy, unstructured reply. I've been writting it whilst making tea, buying parts and watching the footy.
Good luck with your choice. You DEFFINATELY won't regret an Ed30
Nick