I have found that dealers and "big" money clients tend to get higher grades than us normal collectors. Of course the grading services will deny that but it is a lifelong fact in my opinion. They have to take care of their big business so to speak!
The guy who taught me everything I knew about grading was first a professional fotoshopper and then a coindealer until his wife left him
He did estate purchases and retail sales
When you submit your coins ten at the time every week you tend to be known as
somebody who needs to be satisfied or he goes to the competition
The most honest seems to be NGC , when they make a mistake it is because they got
a new grader or somebody who had a very nice night behind him .