When I read that Russell was especially struck in McAuley’s novel by the “density with which its physical world is imagined and the way understanding this world and its structures and processes permeate the sensibilities of several of the characters and finally the novel itself,” I immediately thought not of O’Brian’s Aubrey-Maturin novels — though those are indeed excellent examples — but of Dickens. Bleak House, Great Expectations and Little Dorrit, to name only three, are about characters coming to understand their “world and its structures and processes,” however painfully, and the prospect of immersion in that world is largely what keeps Dickens’ readers coming back.
Dickens’ characters, however, do not transform their world. Individual circumstances do get transformed, however melodramatically and unconvincingly (the Cratchit family’s salvation is downright plausible compared to, say, Little Dorrit’s) — but Dickens’ tangled, grimy, glorious, awful, unfair world grinds on, indeed tends to reassert itself right over the bodies of various luckless characters (the elder Dorrit, Fagin’s Nancy). So this is one difference between Dickens and McAuley, in whose fiction, in Russell’s words, “transforming the world is what its characters aspire to do–not as metaphor or symbolic action … but in literal fact.”
Transforming the British Navy isn’t the goal of Aubrey and Maturin, either (they don’t rock the boat, pardon the pun), any more than Sharpe and Harper in Bernard Cornwell’s novels (or, God knows, Flashman in George MacDonald Fraser’s novels) seek to transform the British Army. But here the distinction may not be between sf and non-sf, but between one-off novels and series novels. If the world really got transformed in a series novel, the series might end, and no one would be happy. Harry Harrison’s Slippery Jim DiGriz, to name the first example that comes to mind, likes his world just the way it is. But as I type this, I remember a sf series character who is, indeed, transformative: Isaac Asimov’s Hari Seldon.