I think mine is V Brake but I'm not sure. I'm ordering the Salmons as soon as I make that determination.
No, according to the Giant web site, the Defy 2 has Tektro TK-R340 caliper brakes. Also from the picture on the web site, it has brake "shoes" (i.e. one piece brake blocks) rather than holders with replacable insert pads.
I recommend you buy two sets of Kool Stop's "Dura Type" pad holders and the included insert pads. These will replace your current shoes and thereafter let you just replace the inserts. You want these:
http://www.koolstop.com/english/road_pad.html