I have used Finale for years and finally decided to have a go at Sibelius. It is definitely nicer and more user-friendly than Finale, and runs extremely well on my Imac, but does not get on with my Windows 7 laptop! Using the DS driver the rhythm is unsteady. Using Asioforall worked for a couple of days after which the sound became grotesquely garbled. Using the MME driver the sound is garbled on startup, I then have to load the Asioforall and then reload the MME for it to work; it does work well after all this, but I think Sibelius have to put their house in order regarding Windows 7! Finale works fine on the laptop.
Later addition -
I have now been using Sibelius for the best part of a year, it is very user-friendly and printouts are excellent. I still have the above problem, although once I have gone through the startup rigmarole everything works fine.
Just a couple of other (interconnected) points - 1/ triplets and other tuplets are a pain to write in Sibelius - every tuplet has to be specified in advance and if you try to edit them the notes disappear! 2/ unlike in Finale, the length of notes cannot be much edited. In Finale, if you have a 34 bar consisted of 3 crochets and you want to change it to 1 minim and 2 quavers, you simply change the length of the notes. In Sibelius as soon as you turn the first crochet into a minim, the other notes vanish! Likewize in Finale if you want to copy a section of music, you can simply enter it all in quavers or whatever and do the note lengths afterwards, and the music will overflow from bar to bar. Maybe the next version will sort this out?
But in general Sibelius is a more user-friendly program than Finale and I now use it exclusively.