Here are some of my tweaked setups for the MP10. The first 2 are tweaks to the Piano Concert 1 and 2 presets, including some EQ:
Big Concert 1
Big Concert 2

These two are meant to sound like that old neglected upright that your grandma used to play. Play with the temperment setting (press the edit button, then scroll down to 4-Tuning) to get a more out of tune sound. I created a custom temperament by randomly tuning keys 5-20 cents sharp or flat. Pythagorus sounds pretty "good."
Gramma's Piano
Gramma's Oldie

Once you download, you'll have to delete the .txt extension so that it ends with .km6 so that the MP10 will recognize it.

If there are any other MP10 owners who have tweaked the factory sounds, please share your favorites.