I've purchesed error coins from Fred Weinberg for over a decade and have purchased, or should I say, was high bidder on a number of PCGS certified world errors that I believed were graded on the high side... If memory serves, I also believe Fred is a consultant for PCGS error coins... I believe it all comes down too "who you know" with the top
TPG services and the dealers seem to get higher grades then the average Joe sending in a few coins (just my personal opinion)... Reguardless, I still respect Fred Weinberg for his vast knowledge when it comes to error coins, and his personal attention he has provided me over the years...
On a personal note, years back I purchased a 1998 Quad Strike
LMC from Fred graded PCGS MS65... I also purchased a 2003d Quad Strike
LMC raw from another error coin seller located in California (in fact, Fred was also bidding on this same coin, as other well known error dealers)...
I sent the 2003d to SEGS for certification and received the same grade, MS65 on this... While many here in this forum have the belief that if it's not in one of the top three holders, the coin is either counterfeit or overgraded... My SEGS Quadstrike has much more eye appeal in a side-by-side comparison then its PCGS Quadstrike counterpart that has me believe that the PCGS error is overgraded, or dare I say, the SEGS error may be undergraded...
I also believe that when it comes to errors, the grade is not as important as the error designation on the holder...