Of course the answer is that you can have 2 tools working on the part at the same time, thereby reducing cycle time. A 4 axis process can see cycle time reductions of up to 40%.
Ten Commandments of CNC machine care Thou shalt check oil levels-headstock, hydraulic, way lube, etc. (Do this every day, not just when the inspiration strikes.)
Now you can get accuracies within .014 microns in all 5 axis on a Millac 800VH machine! The R-Direction is within .024 microns in all 5 Axis also. Watch the video below to see the proof!