not really sure. ive been on the onza and its really nice and flicky. never been on the yaabaa sorry.
they both have vee's . I chose it for you as there good learners bikes . maybe go for a onza bird as a front disc aswell.
both good learner bikes..
down to how much you wanna spend. e.g a onza blade is £530 ., but it has hs33@s and disc..
hope im helping ..
matt