I quibble with you there. "With all quirks and complexity" is grammatically correct and understandable as it is. I agree that "with all its quirks and complexit

I quibble with you there. "With all quirks and complexity" is grammatically correct and understandable as it is. I agree that "with all its quirks and complexity" is more idiomatic, though. For what it's worth, I read it as "with all its quirks and complexity" because my brain just filled in the "its" I expected, which it might not have done if the English had been worse.