Hulk is a lot more "fun". Unless you sit at the back or are towards the end of their major maintenance cycles, the ride is very smooth. The feeling of getting shot out of the barrel is exhilerating.
For us Dueling Dragons is fun but also terrifying. If you get to sit in front, having your legs hang down as the Dragons plunge over the peak into that first steep drop - also sitting in front and seeing the other car come at you is unnerving.
So, for us, it is terrifying fun vs. exhileration fun.....