Even though hide-a-beds used to get a bad rap for saggy mattresses and uncomfortable bars and springs, the good news is that the latest sleeper sofas are not only easy on the eyes, they’re also easy on the back. Cheap? Not usually. But stylish and comfortable? You bet. Clever too. From sleek futon-style daybeds to modern king-sized sleeper sofas with Tempur-Pedic mattresses, we share 11 new designs, just in time for holiday guests.