The difference is minor, only about 1hp and a tiny bit more torque.
I was faster 2up on my Agility 125 then I could have ever been on a rather powerful
liquid cooled 50cc scoot when I was riding solo (and that thing could hit 50mph).
Cruising and acceleration from the lights both.
The Agility's seat (size, padding and positioning) will be more comfortable for 2up
then on the Super 8 too.