disadvantages of a lighter flywheel will result in more rpms lost between shifts,however,as opposed to a heavier flywheel,you can gain them back quicker.it is up to you on which weight you go with,either way,your gonna have to learn how to launch with it,bc it will in fact be totally different than normal.so,if you've never driven with a lightened wheel,id go with a mid weight,such as 11lb,however,just like anything you will be able to learn to drive with any,so you may dive right into an 8lb.the choice is yours ultimatly