I switched from finale to sibelius 3-4 years ago when I became absolutely fed up with Finale\'s abysmal \"upgrades\" which always seemed to be bug fixes which intoduced even more bugs. This was as of Finale 98, so it\'s been awhile. People that I know who still use Finale say that it\'s gotten much better, Sibelius having been the kick in the butt that Coda needed.
Why don\'t you download the demo and see how you like it? Both programs offer similar functionality, but I think Finale remains more of an industry standard if you need to interface with others.
One thing that I find really annoying about Sibelius, is that every time I have to look in the manual for something, it seems like there is some wording like \"and we found a really clever solution to this by doing. . .\" I always find myself thinking \"if it were so clever, I wouldn\'t be having to look in the manual now, would I?\"
So I guess my point is that the grass isn\'t always as green as it appears from the other side.
All major notation programs run much better on PC than Mac. The answer will also depend partly on the OS you plan on running (OSX performance with notation programs is not as good as OS9 right now). This being said, Sibelius performance on Mac OS9 is as good as any major notation program, provided you have a fast Mac (on slower Macs, Finale\'s performance is definitely better).
I\'m not exactly sure why the performance of notation programs is so poor on Mac. But I can say that now that I\'ve worked with notation programs on PC, I CAN\'T work on Macs any more. The performance difference IS that large. Finale runs faster and more smoothly on my Pentium II 450 than Finale or Sibelius run on my Mac G4 733MHz with 640MB of ram in OS 9.2 or Jaguar. It seems strange that these programs run better on $300 PC\'s than they do on $3000 Macs, but it\'s true.
I just want to point out that as far as output is concerned, Finale IS considered by almost all publishers to be superior to Sibelius. There are a few publishers left who will still swear Score is the best for getting the absolute perfect look. I\'ve never spoken to a true expert user of both Finale and Sibelius who doesn\'t feel the output obtainable in Finale is superior to what can be done with Sibelius. There is no question that Finale has more power. Sibelius strength lies in its ease of learning. After you\'ve learned either Sibelius or Finale, both are extremely easy and fast to use.