Your comments

I absolutely agree with this! I have put a lot of time and effort into my assignments, but now that I've started grading, it's become so frustrating and frankly discouraging, because I'm obliged to give "Outstanding" to slapdash assignments that technically answer all of the requirements but are so, so poorly written and have clearly been written without any research or thought at all. 

I would really like to see the system recalibrated so that those who submit outstanding work are properly rewarded for it - either through an additional bonus of some sort, as Cade suggests, or by recalibrating the grading scale so that you can only earn an "Outstanding" for truly excellent work.