Cross grade?

I have a 1st edition base charizard that would have graded an 8 but psa gave it a 6 because it is very obviously off centered. No holo scratches or silvering in the front,no creases or bends and some whiting in the back(what one would expect on a grade 8 but a clean card nonetheless.
Question: would it be worth the trouble to send it to becket hoping for at least a 7 and hoping that the subgrades would explain the card condition better and make it easier to sell.
Would you rather have a psa 6 or a becket 7?
Thanks

@frankr, I moved your previous post to the Giant Professional Grading Thread, the correct place for these questions. You can find the discussion there!