Feature:
I find the overall interface, audio tools, ACID loop support, integrated synths, and deep MIDI editing the most useful features. The bonus plug-ins in XL are very useful. I'm now using it's rewire support to work with project5 and Reason, and that is also working well. Least useful would probably be the light version of the Live Synth Pro because after a month you can only use small size SF banks. It would have been better with VST support, but I have the adapter for that and it works fine for me.

Quality:
I found a few bugs in the initial 2.0 version, but now that 2.2 is out, It's been smooth sailing.

Value:
I wish this were around 10 years ago when I spent thousands of dollars to get about 1% of the capabilities found in Sonar.

Desirability:
The features make it sexy, but I guess it could look a little sexier. Does that really matter though?

Sound:
Sonar is a transparent audio application. What I mean by that is it doesn't color my audio when I record. Well that is unless I want it to :)

Support:
I haven't really needed service or support so I guess that's the best it could be.

Overall:
I'll keep this until Cakewalk releases version 3.0.