Defy used to be the Giant relaxed fit bike, both Al and CF. Now CF Defies are called Defy and Al Defies are called Contends. if you get a Contend or an old Al Defy, don't get the most basic base model. I think one or two rungs up the quality ladder the frame improves drastically ... might be Aluxx to Aluxx II or something, i forget. Ask around. From what i read at the time, the better frame and frame technology is the same one shared all the way to to the top tier of Giant bikes, while the low-level frame is just a decent Al frame.
if you get a CF Defy, no such issue as i recall, but again, multiple sources might reduce the risk of error.