hello..........I am Brian from the colonies(Las Vegas, Nevada).................I have been collecting since 2017................I am a member of both PCGS and NGC registries..................I have found the PCGS people and registry system to be more responsive and open to the desires of the customer and a joy to work with...................on the other hand the NGC registry is simpler and therefore easier to use, but limited.....and the hired help less capable if not rude nor in some cases even aware of what collectors want or need.........................of course the available work forces are very different....Florida is less educated and California more educated........it is hard to find new employees either place..................as you may have noted a PCGS PR69 is many times going to be a NGC PF70.........certainly not for sure................I "feel" that the PCGS grading standards are a bit higher than the NGC but both are certainly higher and more accurate than my poor abilities............the rule thumb seems to be never cross over an NGC slab to PCGS because you may loose a grade.
as I mentioned, I collect both.........but only Queen Elizabeth II gold sovereigns............the NGCs tend to cost less and the PCGSs cost more........and in many years the the NGC slabs are more available..................there are simply more coins graded by NGC...(supply and demand)...so some NGC slabs are dirt...like the 2013-I...it is hard to sell one for much over spot...and the same for 1918-i even though so many want to say that it is "Rare"...it is not.
in the end both companies do the best they can given their respective situations.......both growing like mad and having to contend with work force problems
have a good day
Brian