Yeah, it would be nice if there were more over-the-shoulder mix tutorials done in SONAR. I too have seen the offering from Groove 3, and one of our forum users did his own start-to-finish mix series in SONAR. But aside from those, yeah, Pro Tools is almost always the DAW of choice.
 
Ultimately it's the techniques that matter and they apply to any DAW, but I agree...it would be nice to see someone mix a song using the same software I'm using for a change. :)