I've owned a 2006 V6 and now own a 2010 GT.
The factory air induction system on the 05-09 models blows. Replacing it with an aftermarket cold air intake (i.e. Steeda, JLT, Airaid) will provide worthwhile gains.
The factory cold air induction system (Ford's name for 'CAI') that comes standard on the 2010+ models is efficient and not necessarily worth replacing.
2010 GT Premium - Automatic - Torch Red