First, I really appreciate that other people left reviews here...it really made me feel comfortable making a purchase like this (online, without testing it) and in deciding on this specific memory-foam mattress. I purchased this mattress at Overstock on a Friday, got free shipping (with the O Club Membership---which immediately pays for itself) and it arrived the next Tuesday! **** You may want to sign up on Overstock's Site as a regular member before your purchase, as they send out 10% e-mail coupons **** As other reviewers stated, it's hard to believe that a California-sized king bed can come in a box that's roughly four feet high by two feet wide (87 pounds), but it does..... and it's perfectly fine! The bed comes in a plastic bag that is surrounded by a stronger threaded plastic outer layer (which keeps it compressed), and then of course the shipping box. You just simply take the bed out of the box, place the wrapped bed on your frame or box springs, carefully cut the outer layer off with scissors, and then watch your bed grow to full size! Remove the lighter inner plastic cover and you're ready to go. My wife has a very good sense of smell and said she could barely detect an odor from the bed. Once you let the bed stretch a little (5 minutes), the instructions say that it's perfectly O.K. to lay on the bed and sleep on it immediately, which we did. We kept our existing bed springs and just replaced our mattress. This 8" Serta exactly replaces the length and width of the Cal King mattress we had and we use regular Cal King sheets with it. It also is a full 8" high, as described. The comfort of this bed is fabulous. Because it's a memory foam bed, it adjusts to your size and weight and then sort of molds you into it. It is a bit firm, in the sense that once you sink in it stops moving. As others have noted, because this mattress is probably unlike anything else you've ever slept on, it's just feels different at first and it takes a short while to adjust to this feel. What feels like firm at first feels great a couple of days into sleepng on it and the discomfort and pain we had been feeling from our old spring mattress just disappeared!!! The only way I can describe it is that it feels like there's nothing around you, as if you were laying directly on the ground, but yet it's super comfortable ---- i.e. natural!!! A great feel and experience! By the way, one concern we had was that it might heat up with our body temps and be too warm--- we've found just the opposite and find both the comfort and the coolness to be excellent. If you're a light sleeper and your partner comes to bed later, you'll love this bed. I'm a night person and my wife says she doesn't ever wake up now / know that I came in later!!!! We joked there's not enough hours in the day to enjoy our bed and are both loving it. Again, like others mentioned, you can always add an affordable feather top if you need more of the spring-like cushion that a traditional mattress provides....we're happy with the way it is and are sleeping better than we ever have! Finally, I just used our O Rewards (credit, after joining the club, from your purchases toward future purchases) toward an area rug with, of course a 10% off coupon.... and the product and delivery were once again, perfect. I am a customer who expects very good service and have been totally thrilled with the e-mail communications, tracking numbers, and everything that Overstock has provided us in our experiences so far! Happy shopping to all of you and thanks to Overstock for the value and the service--- we will definitely be shopping with them again in the near future!!!