I don't think any one user uses all the features in Sonar. Its a great testament that so many can use Sonar for their particular style or type of work.
At one point I thought a user is going to be in trouble trying to learn Sonar being as deep and capable as it is. I don't hold that view anymore. One reason is the Skylight GUI. It allows CW to add features without interfering with its most important functions. Another is take it one feature at a time. No one needs to learn them all in one day.
I like Danny's way of doing things. Of course one has to remember a feature exists before one can explore it. I have on occasion forgotten all about a feature. LOL But I'm getting old.

Which is a good thing when one considers the alternative!