I agree with Fran - This is a case of apples and oranges. The Korg doesn't even have internal speakers, for starters. I was a fan of the I5-S for a while, and I know what you mean about the bass. I think Korg bass patterns are the best, next to the X1 of course! The Solton shines in EVERY way compared to the Ix-300, you would not miss a thing, except maybe the small size and weight.
Everyone, and everything I listen to is my teacher. Every instrument, every voice, every sound in nature ... they are all my private tutor ... 24/7 for free.