I used Finale for years when my "chops" were not quite up to the
task of playing an accompaniment to a song or score I was learning.
Got relatively fast inputting with keyboard shortcuts, and a great help
was having my Clavinova right next to the computer so I could add notes
manually if I wanted to.

Ultimately though, I believe the "best" solution is to get really
friendly with a true pianist who you can record while playing the piece
into your software, slow or fast, and then you can clean it up or
modify as desired.  Pay him or her well and you will have an
invaluable resource.  Save a lot of your own precious time, too.

Just my two 32nds.

Claudine Jones
San Francisco Bay Area