Persuasion, written toward the end of Jane Austen's life (and published posthumously) is often considered her quietest work. But to me it feels colder, somehow, than her other work. Although Austen has always poked at the pretensions of her characters (Mr. Collins in Pride and Prejudice, for example), here the vain and thoughtless characters (mostly Ann Elliot's family) take up a disproportionate share of space.
Another lack is that Ann Elliot herself doesn't really change through the course of the novel. She's correct in just about everything she does, so we lose the narrative arc of, say, Emma's realization of her fallibility or of Lizzie Bennett's realization of her prejudice.
It's of course not a bad novel by any means (and her skewering of her characters' vanity is very funny), but I think I would rather re-read Emma or Pride and Prejudice than come back to Persuasion.