I would concur with Craig's post above - I am a keyboard player, who plays some guitar and sings backup vocals at church.
I almost always am focused on dealing with MIDI, and only marginally do I go into anything fancy on the resulting audio - some levels, EQ, reverb, delay, compression - all standard stuff.
There are GIANT swaths of Sonar that I just never ever deal with, comping, take lanes, screen sets, and I likely will never end up dealing with any of those areas, despite having worked with Sonar since it was in DOS form.
Whenever I DO see something come along that looks beneficial to MY needs, it is at THAT point that I will invest the time needed to work with that piece of things.
My advice is to always review any new features that come along, because any given month may well bring something to benefit YOUR ways of doing things, and make sure you have reviewed all of the features that are already there - not from so much a stand point of learning all of those features - just making sure you know what those features bring to the table - in case any of them might help you with what you are doing and how you are working.
Here is an off the top of the head analogy - you enroll in a college, and are taking music courses there - the school offers degree programs in astrophysics, and biology. Would you feel a need to take any of those courses just because the school featured them? Nope - you would take the courses needed for you to get the training in music. And even with the music courses - I wouldn't take a bunch of classes in singing, if I played the clarinet.
Bob Bone