I write a lot of piano music, so I hope you'll find a better way to handle cross-staff notation. In Sibelius I always have to adjust cross-staff slurs, and every time I change staff spacing I have to adjust them again. Also accents and such go wrong, also default accidentals. An ideal solution would treat a grand staff more like a single staff, since that's how it's used.

One more big problem is grace notes before a barline. An ideal solution would be to let us attach grace notes to the actual barline.