It only made Kuririn and Gohan's powers rise from around the 1500 mark to "over 10,000" which makes it at best a sub-10 fold increase. Might even get less effective because Goku was already well trained with his gravity training. The only change I would imagine would be that either Goku defeats Ginyu before he can even attempt his body change, or if Ginyu succeeds, he is powerful enough to defeat even Vegeta and the heroes lose.