Let me know how it works out for you. When my old "commuter" dies, I, too, will be buying my first 'real' road bike. And I, too, will most likely go for the Defy (US version) - not sure which spec'd model, though.
I am the biggest Giant fanboi out there, due to my love of their mountain bikes.
(Of course, if I happened to be willed a nice Waterford, then all bets are off)