Sorry Angelo, I don't think I understand the question. Are you asking whether any of us actually composes with Sibelius or Finale, rather than just using them for notation? If so, yes, I compose all my concert works in Sibelius currently, Finale up to a couple of years ago. The piece "reflectere" in the projects section was composed in Finale, and the playback is direct from Finale as well. For the occasional commercial project I will also compose directly into Sibelius now. It's just a matter of the sort of writing that's required. I never play/record anything into the notation programs, I just punch it directly into the score. So, if it's a project for which I feel I need to see it on "paper", I'll write it in Sibelius (or Finale), while if it's something I feel I want to play/record I'll use Logic or Live. If somebody would make a sequencer that really used notation as a foundation, I'd be ecstatic, since I could finally unify all this into one workflow (except for the fact that I've recently picked up Live, and am really enjoying it for certain projects). As it is, I can't stand looking at the garbled notation output generated by notation programs or notation interfaces (i.e., in Logic) when trying to record "live" input. It just feels like such a profound waste of time to unscramble it back into sensible notation... my keyboard skills are pretty awful, though, so I'm not helping matters in that department I'm sure.
There's a notation interface in the ftm package for MaxMSP which uses a clever combination of a musical staff to indicate pitch, and piano scroll-like bars to indicate duration. If something like this could be used in a professional sequencer, as a method for viewing recorded input and editing its rhythmic representation, it would be a huge step in the right direction. But I'm afraid that the music literate are not a huge priority for sequencer developers... which I don't quite understand... (well, I suppose I do: money, money, money.)
J.