The differences between the Pa1x and 2X are really minimal unless you do a lot of sampling or are likely to import large commercial samples. Of course the polyphony is an extra added benefit but in reality you would not notice it unless you use heavy layered multiple phat sweeping strings and chords throughout a song or sequence.

The Pa range is geared to the all round musician who is comfortable in both live performance and studio/recording/sound creation etc use.

This is where the Korg range diferentiates itself from other arranger keyboards on the market.