I'm new to this mode..

I was advised by someone I think is knowledgeable, and certainly more so than me, to orient my cross polarized 2m Yagi so that the elements resemble an X rather than a +. Easily enough done...what's the advantage? 

It's my understanding that the two sets of elements are out of phase by 90° & combined at the common feed point to emulate circular polarization. How does the rotation along the boom axis make a difference?

Seeking understanding...