personally I don't like expo, it make the plane feel to heavy in the sticks for me. but to each his own. if the roll rate was too much, two things come to mind.
1. your used to a highwing trainer, and your over sticking the extra.
2. you have your rate set a little too high for your experiance level, and your over sticking when you fly.

the one word I'll repeat a million times when I'm teaching some one is finesse. next time you fly it, once airborne and at a safe altitude throttle back and just fly a wide pattern to get a feel for how responsive you have it set up. if you don't have a gentle touch then use expo, but I would advise having an experianced co-pilot around just incase you get in over your head. my SSE was my third low wing plane, the second was a BH speed air40, which is kind of a low wing trainer. the SSE is way easier to land