PSA 7.5, 8.5 - BGS 8.5 - Thoughts on the between grades?

General
1

Haven’t been able to find much info on this but how are these middle grades given? Are these grades usually looked down upon or avoided?

Don’t see them as much so wonder why PSA has these grades.

3

www.elitefourum.com/t/the-giant-professional-grading-thread/30930/1