Just a quick note on the boutique at T5 Heathrow; unless you are flying outside of EU, you will be charged the same price as the regular boutiques in the UK. As this is higher than the euro prices, better to shop in Euroland if you can when you get there. Most unhappy camper when we were at the airport last week and discovered this!:cry:
As an aside, coming back through Rome's Fiumicino airport I was delighted to get the pair of Valentino boots that I had been after but didn't have my size at the Piazza di Spagna boutique, at a 20% discount and with no problem that I was travelling within the EU. Go figure!