KORG PA1000 or PA5X

[ArmandoKorg]

I currently own PA500 and am thinking of upgrading. Debating if i need PA5X or PA1000.
I am not a keyboard player and will not perform on stage. I will use it primarily to compose tracks with styles and record them.
Is PA5X providing that much advantage to justify the price difference or would PA1000 be just fine in your experience?
I currently do this on PA500 but the output is not of great quality. Also I record the song in the sequencer (quick record) but make mistakes and it is very panful to correct it in 'Step Backing Sequence'. Do either of the two provide better editing interface?

Thank you in advance for any advice!