Just got them and put on the bed LAST NIGHT!!! I have a big mattress and have such a hard time getting sheets TO FIT that don't roll up under you in your sleep.. THESE FIT - were actually a lil bit too big (NEVER SEEN THAT COMIN) Elastic all the way around for a secure fit, THEY FEEL FANTASTIC, & keep you cool! At  least me anyway!! 
I'M BUYIN MORE SETS!