Admittedly, I am firmly in the Yamaha Arranger Keyboard Camp. As you probably know, many of the members on this forum are entertainers (one-man-keyboard artists) and they all play really well. Because of that factor, many have different needs than a "rank amateur" like me. I use my PSR-S910 Arranger for creating new songs and I use the intro, style, multi-pads and other features of the keyboard to create a demo of what I've written.
I play only chords and after significant set-up time, the "board" pretty well does the rest for me. I carefully select the individual instruments, adjust the volume for each one and do my best to press all the right buttons at the correct time and sequence. (Easy-peasy!) When I finally get the song recorded the way I want it to sound, I transfer the WAV file from my Digital Recorder into my computer for further editing.
The beauty of all this method is that I can save the setup and re-use it to keep recording if my first "take" ends up having some kind of glitch. (I don't think of myself as a singer but my only other option would be to pay somebody to do it for me... and that would take time and money.) I am fairly prolific and now have a catalog of recorded songs and compositions nearing 1100. I register many of my songs with ASCAP if I believe they have any commercial potential for other artists to "cover" as part of an album or a "single."
Nothing wrong with Korg or the other "boards." It is a bit like buying an automobile. Personal taste. I found it easier to "migrate from a Yamaha PSR-2000 to the 910... and really want a 970 when they become more affordable after the next model change.
Best of luck to you. ----Dave Rice
http://www.ShowCaseYourMusic.com/DaveRice/