Cakewalk's OK but it used to have problems (which may have been ironed out - it's a while since I programmed) such as not being able to specify a certain number of bars per stave, which is so useful if you need to give out the dots for quick sightreading. The ideal situation that gives you the best of all worlds and quick results is to program with a midi sequencer like Cakewalk or Cubase and then shift the finished product over to Sibelius for tarting up as a score - cost-wise, I noticed someone has already mentioned that there are cracked copies available, not that I'd know anything about that...