John,
many original PA1X styles have been revoiced and take advantage of the new guitar mode to add realism to the guitar tracks; Korg is actually realeasing new styles every month.
That said, I think that the main reason to choose a PA2X over a PA1X are not the styles, but features like the double polyphony, the greatly increased RAM and so on.
Good luck with your choice.
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Korg Kronos 61 and PA3X-Pro76, Roland G-70, BK7-m and Integra 7, Casio PX-5S, Fender Stratocaster with Fralin pickups, Fender Stratocaster with Kinman pickups, vintage Gibson SG standard.