Giant TCR's are widely considered among our all time favorite bikes among all the riders I have been riding with over the years.
Bikes and geometries are personal. Bikes either seem to work for you or not. The aero of one over the other is pretty insignificant IMHO. If you're not comfortable on it or enjoy riding it then all the aero in the world won't help. Besides Giant has a wind-tunnel for testing and I am sure they can list as much biased data as Cervelo can.
The only time I would ever favor aero in a bike selection is when discussing a new TT bike and only if I was racing on it (which I mean why would you own a TT bike unless you were racing on it).