I just completed a review for the NSF on a very interesting proposal in the ecological, population biology etc. area. Probably because I am foreign national, this is the first time (maybe the second and the first time I declined?) I was asked to provide a review. After completing my summary I had to choose the final grade. I thought Very Good was the right grade because they were a couple of things that needed to be addresses, but I remembered what John Boyd was saying about "grades" in the army, where being merely excellent meant not being suitable for promotion. "Colonel is excellent in every aspect" meant between the lines that the Colonel was getting sacked. You needed to be super or ultra excellent in every aspect and more. Boyd is an interesting read by the way, although apparently his influence in the military has been in the neighborhood of nothing ("folk hero" has been the definition of someone in the know). One time I also took inspiration from his analysis and synthesis dual approach to learning and understanding for my teaching statement in a job application, but apparently the committee thought I was merely excellent and not super excellent. Now that I remember (refresher here) Boyd was also very very weird, so maybe taking inspiration from his bizarre views was not a good strategy. Better in any case than being boring (remember than interesting is better than boring and fun is better than not fun, although right is most of the time better than wrong and this may create conflicts with the fun part) with all the "my mission in life is teaching undergrads and please give me a job and I will teach 4 courses each quarter (give me a job is the lynchpin, by the way)". So, I might propose again the analysis/synthesis destruction/creation dual approach, just for the fun of it (and I also believe it is an interesting approach, at least it was at the time). I will tell you how it goes. By the way, I enjoying teaching undergrads.
Getting back to grades, I googled online and I came across this 3 years old post from the popular Female Professor blog. After reading that Very Good is not actually very good, but, meh, kinda good, I bumped my grade to Excellent since I believe that the proposal should get funded. Be aware fellow reviewers that what you write should reflect what you think as well as what they think you are thinking. Since you do not know what they are thinking, bumping up might be generally a good strategy. At least, that was my choice.