"Good for the Casual User"

Feature:
It comes with a nice mousepad which is helpful in memorizing shortcuts. There are a ton of features that both Finale and Sibelius lack... too many to comment on individually. To give some idea though, there is often only one way to do something in Sibelius whereas Finale offers several. This can make Finale more confusing at first, but once learned it also makes Finale faster than Sibelius since the complexity and variety of music calls for flexibility on the part of the software. An example would be triplet entry. In Sibelius, if you're entering a piece with consecutive triplets, you have to press the triplet shortcut combination for each triplet. Finale can do this, but also allows you to lock in triplets so that each set of three notes gets entered as a triplet automatically. Hundreds of things like this add up to make Finale faster to the experienced user.

Quality:
The software is reliable as far as music software goes. I can crash it easily enough, but generally speaking the crashes are not in commonly used functions, so most people won't run into them regularly. Finale and Sibelius are both relatively stable.

Value:
Yes, overall the price is fair. If you intend to use notation software once in a while, maybe with a few months between uses, I think Sibelius is probably the program to get. If your use will be more regular and you'll be keeping yourself fairly current with the software, I'd go with Finale.

Desirability:
Sibelius is an attractive program which is pretty consistent in its design (which makes use easier). Many things are designed with simplicity as the emphasis, and this unfortunately does greatly reduce the speed.

Sound:
Sibelius playback is decent, although lacking compared to its primary competitor, Finale. The program will interpret most score markings and attempt to play them back. Compared to Finale however the intelligence of Sibelius' Espressivo is pretty poor compared to the Human Playback in Finale. The program basically uses a random number sequence to determine which notes should be loud and soft, while Finale looks at the phrasing of the music. Finale is also more intelligent about the way it interprets some musical elements. And perhaps most importantly, Finale gives a lot more in the way of control over the playback.

Support:
Sibelius provides excellent customer service and technical support. Both Finale and Sibelius support teams have gained recognition for being at the top of the industry. You won't go wrong here.

Overall:
I teach both Finale and Sibelius, so I'll be using both for a long while.