I stopped after Malloreon more because my interests changed. Finding out their history hasn’t changed anything for me. But Marion Zimmerman Bradley for some reason has and I have no desire to read any of her books ever again.
As for MZB, I agree completely. No desire at all.
WRT to O'Brian, though--it's clear, as the OP notes, that he knew his faults, recognizes them in his characters, particularly Maturin, and shows them for what they are. To put it another way, his faults don't "poison" his books from within.
In the Sparhawk series, Faran was the likeable character.