I used the comping feature last night on an old song that I was doing a redo of the vocals. It was stared in Sonar 8, vocals redid in X2, and now working with it in X3.
I have to say that the comping feature is just a work of art. Once you get use to it, learn the key commands, it's just a joy to work with.
And once I had my choices selected, I was able to use Melodyne to correct some notes very easily.
X3 rocks