I think the biggest problem is that 10ms is more than enough to throw off a performer because it feels like a lag between when you hit the key and the note soun

I think the biggest problem is that 10ms is more than enough to throw off a performer because it feels like a lag between when you hit the key and the note sounds. This makes it hard to play proficiently for anything with a fast tempo because it feels like the sound engine isn't keeping up with you. For an audience, 10ms is going to feel like sloppy timing. That will be more of an issue with tightly timed music (techno/EDM) and less with a slow jazz ballad.