i would recommend taking the class versus just the test. for a couple reasons...
one, taking the test is pretty hard on a sportbike because the handlebars do not have a good turning radius because the hit the tank, and you have to be able to do some tight corner turning.
two, if you drop the bike in class, no biggie, even if you break it, my gf dropped hers and snapped the mirror off/dented the tank, they said oh well, get up and keep going.
three, you get to ride different kinds of bikes, I took mine on a dualsport, which i'd never ridden but it was fun as hell to play around on.