I love the new mixer in Cubase 7.0.6 and in Cubase 7.5 they have taken it even further.
Tip of the Day
I use the “MIXIER 2” or “MIXER 3” as my main mixer. 
That solve the most problems you will ever encounter regarding Mixer problems /bugs. I don’t know why “MIXER 1” “F3” has all the issues or had the most of all issues when the rest of mixers worked fine? To work around it, use MIXER 2 or MIXER 3= no issues.
Best Regards
Freddie