Those are some good points.
I guess, for me, I think the ability to use lighter weight rims can offset some of the rotor weight. I still don't think hydraulic disc brakes are going to be of any benefit to more than maybe 5% of the cyclist out there.
I am concerned about something else, when using the brake, you can argue that is when there is a lot of force on the front wheel but that "pinch"point at the brakes might help by offering a temporary support point during unusual applied forces. Time for some research...
Any comments about the Giant Defy Advanced Pro2? Other recommendations for an A rider riding 30-60 miles at a time? I want speed, lightweight, some comfort (but will trade comfort for more speed), Ultegra 11 speed, strong wheels and carbon.