I thought GB had a different duty free catalogue - it has been a while since I flew them though.
Personally I buy 400 Silk Cut for a couple of colleagoues. It's normally more expensive than the airport, but if I have to cart them around I want a reward - the miles.
Echoing
awm's comments, it would be nice to see some imaginative exclusives of some decent products - but nothing too gmicky like reversible belts. How about some BA branded leather travel goods (NO smutty remarks please

).