I'd say the fact that you're concerned about driving too fast is a good thing. I'm finding similar urges with my new DT. Gone are the days of being left behind by people who cut me off, tailgate me, or drive while on their cells. The urge to chase them down is there, with the ability to deliver. But that's road rage. Giving in to that leads to worse things.
Not sure if I read it somewhere, or an instructor told me, but its something to think about -- don't drive faster than you can think. Like Mscmkr said Youtube is filled with those idiots. Aa my wife reminds me when we drive, the world looks better at 40 mph, than at 50, 60, 70, or 80.
Just wondering, but wouldn't a Vespa GTS 300 go as fast as your GT? I saw a woman the other day driving one in Philly along a river drive. She was doing 60 + in a 35 road sans helmet, jacket, or eyewear with ballet shoes. Think she had a death wish.
-Wolf