G21 demo this Saturday

So I am going to demo a G21 this Saturday with a buddy of mine. He is relatively new to the tow boat scene so I am trying to help him out.

He is mainly interested in surfing so that will be our primary activity. I currently own a 2015 X-30 so that is what he is going to compare the wave to (as apples to oranges as it might be)

I was mainly wondering about the best surf setup in a G21. A friend of mine that owns one and who's opinion I trust has told me that stock ballast is the best setup he has achieved despite trying different configurations. Anyone know any different? If that is true, that will make my life a lot easier.

I will post a review after of course and will comment on handling, fit and finish, stereo etc.

Thanks!