Do not listen to the naysayers, these sheets ROCK!! I have a regular depth mattress, but there is plenty of spare sheet to handle a thicker matress. Pillowcases might be slightly short, but these sheets are soooo comfy, I got over it! I'm buying more before I can't find them again. Do it, you won't find better for the price.
I read somewhere in another review that these sheets were 'noisy' and could not imagine what that meant. I know now what that means. Rustles a lot when i toss or turn in bed. For Example: i know when my bf is up because i Can hear the sheets rustling from the living room! It's high quality, but feels kind of heavy ( which you would expect in a higher thread count anyways) but a little scratchy also in my opinion. Hoping they get more soft the more I was them, but next time I will probably stick with a 400 TC set. Extra fabric left around the corners if you don't have a deep mattress.
These sheets are wonderful. I love the feel . At first they are a little stiff but after a couple of washings they are great. They are silky & smooth but not so slick that the comforter slides off. I will deffinately be buying another set of these sheets.