It's a bit obvious the remap I would recommend!
My 2.0TDi was remapped at 2 months old, overall mileage since I bought it in September 05 12,800 miles, average mpg over that distance, 49.4mpg and I don't drive it slowly. The best real world car I've ever had. The DSG gearbox is excellent.
To answer your question, if a dealer reflashes the ecu after a remap and clears the remap, we restore the remap without charge, as we keep a detailed log of the remap for each car.
Whichever of the mainstream remaps you choose, you won't regret it.