Probably about as fast at the track.. the DOHC will give a bit more of a torque feeling when driving it due to the way the powerband peaks with the dual cams.

A GTP feels pretty slow other than the first second you rake the throttle in. The powerband stays flat so the feeling of "getting faster" is sorta forgotten... example my buddy has a 650whp n/a SB2, while my 3800 fiero makes 600whp+ and is quite a bit faster, the camaro feels like a rocket ship and my fiero is just a sorta fast boat.