What their argument is is that by being crucified, Jesus paid the penalty that souls would otherwise have to spend in purgatory. The question I had to this would be the case of a man who led a completely evil life, but begged forgiveness at the end of it. The response is that the rewards for a good life would be granted in Heaven, not by less time waiting to get into Heaven. But that would then imply that some in Heaven outrank others.
Not necessarily. I respectfully refer you to C. S. Lewis' The Great Divorce.
Let me me know what you think of it.