The autos are faster, too. I almost got an auto this time but this car will likely get road raced eventually so I need the manual. (what I really need is an auto 5.0 for the 1320 and a Boss for the road course- then a divorce lawyer and a sponsor after that...)
As far as the Boss v/s the GT you can't go wrong either way. If you can swing the extra 7-10 grand for the Boss I'd go for it. Besides the extra power and higher revs it has better suspension, bigger meats out back, awesome seats (that will find their way into my car), looks badass, and a lot of other subtle little things that escape me at the moment.