i dont know if you have tried to create a track from scracth DNJ on your arranger . The clip you posted of the Kronos can be reproduced on just about any arranger if you know how to programme and edit sounds and use your sequencer. The sounds used in the clip was a combination of strings , horns and a synth sweep pad, and a bog standard rock drum kit and a pizzacato sound. All of these are on any MOTL arranger including your psr910 (if you still have it. All you would need to know is how to edit the attack on the strings and the velocity on the horns to create that 'swell' effect and asign the resonance or brightness of the synthpad to your pitch bend wheel or joystick (on the Korg). There was absolutely nothing in that particular clip that even ythe lowliest arranger couldnt do ...if you know how to use the instrument beyond pressing the start and stop button.

As for original content. thats simply down to the skill of the musician and if you cant produce original tracjks and accompaniment on your arranger then you definately wont be able to do it on any workstation. Dont be fooled by the demo.

Most pros dont know half of what an arranger is capable of or they would most likely own one.