Actually, that's quite good, the edge reading is sometimes lost as grades diminish.
Another for the farthing thread from me: Here's a 1694 'no stop after Maria'. A scarce variety, and all the more so in grades above fine.
I think they're getting more accurate with time as they gradually progress in size and importance towards the "senior" auction houses. It wasn't so long ago they their catalogues were just just printed lists but now they rival the biggies and their photographs now surpass Spink. If they would only join the internet bidding world they could even become the best, and their fees are without doubt the best.