Good extension! It does what it says, and the options are pretty flexible.

My only complaints are: a) I wish it cached page data when discarding, b) I wish it wouldn't resume a page just because I've ctrl+tabbed past it; I'd love an option to make it resume on click as in The Great Suspender, and c) I wish it could do more about the FF memory usage, though that last one is as much on Mozilla as the author.