Thank you all for providing your consumptions rate and inputs. It seems that 6-8 hr/QT to be the average for the IO390. From what I have learned about Lycoming engine, using some oil is absolutely normal and sign of healthy engine as too much or too little oil consumption indicates abnormal. As for the oil level, my guide is to put as much as possible without getting it to throw out of the breather. One area that more oil level will help is the oil temp, with more oil you will get a lower oil temp. Also type of flying has a direct effect especially if any aerobatic moves are done.
FWIW, I run my engine a bit harder than the last plane, my typical climb is as full power and then lower the RPM to around 2500 for cruise. I wonder running it harder has an impact on oil consumption!?!?!?