I feel that this should be a critical issue for composers of the digital age.
I've used Sibelius since Sibelius 3. I will go to Finale if I have no other choice. I still use Sibelius 6 and may be happy with it for some time until my PC is too far beyond in years of upgrading to handle old programs. I intend to develop my own for my own purposes in time.
What do you think?