[jdietrich]

As a Sibelius user and jazz musician who writes avant-garde music, I humbly disagree. Classical notation is my native language. It's an odd and idiosyncratic language, but it works. If you need musicians to understand what you've written, it's your only option. I can't read piano roll at tempo and I don't know anyone who can.

Sibelius has fairly good support for swing, shuffle and irregular meter. It has natively supported quartertones since version 6; plugins provide good support for alternative tunings and microtonal composition. Classical notation can get clumsy if you're doing really weird things, but "really weird" is a higher bar than you'd expect.

If you're using timbre as a fundamental expressive element, then a DAW is probably the right tool. At present, we have no useful system for notating synthetic timbres.