I sold my '03 for a 2010, but now I have the 2010 for sale to go back to an '03. It is a tank compared to the '03/'04. The '11s are a little lighter than mine but are still dimensionally HUGE compared to the '03/'04 Cobras. As far as handling, my previous '03 with just some subframe connectors and H&R springs was way more nimble than my '10. The plusses to the GT500 are the interior quality, amenities, and ride comfort. I, however, have found I really don't want these attributes in my weekend toy that will get abused. In the end, I guess it just comes down to what you want: a raw, visceral, relatively light muscle car or heavy, refined, great-looking cruiser? I've decided I want my luxury interior and electronic gizmos in a nice, 4-door daily driver (Acura TSX to be exact). Another plus is that for the price of my '10, I can have an '03 AND a TSX! Hope this helps.
Here's a picture that shows the vehicle size difference pretty well:
Here's a picture that shows the vehicle size difference pretty well: