When you cross the threshold of your surprisingly spacious Harrah's Luxury 1 King Bed Room, you'll want to take a moment to savor the elegant appointments and original artwork. But your strongest urge will probably be to sink into the exclusive-to-Harrah's, pillow-top Simmons Beautyrest mattress. It might have something to do with the fact that it's 5 a.m. and you've been up all night. But we really think it's the mattress. 430 sq. ft.