Nice impressions Donny, shame it's marred by the fill in issue for you. I must admit I hadn't noticed it myself but I will check later on certain styles.

I did notice though and I think I mentioned it to Rikki that the fill ins are slightly different on certain styles that I am very familiar with, especially those taken and filtered down from the T4 such as StadiumRock, that definitely has a different fill in and when I tested the T4 version of it, it played exactly as intended so any reworked styles may have differences that might not always be good.

Maybe as a test, try the same styles you have the problem with if they exist on the previous keyboards, use them on the SX900 and see if the fills have the same problem for you.