There's a reason a player plays either all gut, all poly, or a hybrid. There are advantages and disadvantages to each. Just like there's a reason some players who hybrid their strings likes one or the other in the mains. It all comes down to power, control / spin, and feel. Depending on what is most important to the player he will like one or the other in the mains.
I would like to apologize to anyone I have not offended. Please be patient I will get to you shortly.