The "extra" memory is flash that TI reserved for storing more OS code, but TI doesn't use it. In fact, they're far from using it. You can't use it for long-term storage because TI has code that erases at certain times, but it's fine for use as temporary storage. And he's got a point. Considering how much the swap sector gets programmed/erased during a garbage collect cycle, it can't be any worse.