So-so results as of late I think. Also hard to interpret with the valve cover leak issue. I bought a can of seafoam on sale that I am considering running into each of manifold, oil and fuel sometime soon and get PP in there. (still running the Rotella) From additional reading, I would consider trying GM top end cleaner that seems to have a good reputation.
Mar 1, 2014 158,661 miles
Mar 5, 2014 158,730 miles: Oil level ~75% operating range, just into upper cross-hatch
Mar 11, 2014 158,805 miles: Oil level ~70% oper. Range, just at beginning of upper cross-hatch
Mar 15, 2014 158,914 miles: 253 miles in. Oil level ~70% oper. Range, just at beginning of upper cross-hatch
Mar 21, 2014 159,018 miles: 357 miles in. Oil level ~60% oper. Range
Mar 25, 2014 159,128 miles: 467 miles in. Oil level ~55% oper. Range
Apr 6, 2014 159,354 miles: 693 miles in. Oil level ~35% oper. Range