I'd stick with the Korg, spalding, for the familiaity with the OS and the editing depth. Korg's TOTL release cycle seems to be four years, if their past releases are anything to go by.
Pa1x - 2003
Pa2x - 2007
Pa3x - 2011
Pa4x - 2015 (logically, anyway)

And I'd assume the price would still be well below a T5.