I'm glad to hear you guys found a place that supports your work - I have no idea what Avid was thinking.

I use Sibelius and I compose Choral Music and I'm getting into composing Electronic Acoustic Music.

The biggest issue I've always had was scoring for electronics and alternate instrument techniques: Graphic shapes, filled polygons, freeform lines and curves. Being able to incorporate some of the playback to get at least an idea of what I had written down and be able to demo that to players would be a major plus for me. Right now, I have to use brute force to score the temporal/non-metric sections for the instrumentalists and then draw the graphic objects in another application in a PDF exported version of the score.