Dear David, I'd worked for Years with Finale and Sibelius. Since about 3 years I'm working with lilypond. I choosed it, because I do write my music first by hand and than I do the fair copy with the computer.
In my opinion Lilypond is the most efficient way to do this work, altough I have to admit, that I sometimes miss the so called "look and feel" that I have been used to, when I used Sibelius.