Bests & Worsts Reviews from Amazon

I haven't needed to check the water proofing, and don't know how well the dust mite protection works, but this seems to be a decent mattress cover for the money. It is comfortable on my Sleep Number twin XL, and is not too hot. The only complaints I have are: 1) Washing per the instructions is a bit of a pain, and takes a while before everything is dry. Ultrablock recommends washing before first use. After this inital and 1 subsequent washing, per Ultrablock's recommended schedule, the soft flannel-like side is starting to look like it is degrading, trying to 'pill' in the center of the cover. Doesn't feel uncomfortable, just not sure how long it will last. 2) Even when first put on the bed, it seems to fit a bit less than snug, and by the end of a week it sometimes bunches up under the sheet. I have thought of using some soft-clip sheet tensioner straps to hold it tighter from side to side, but don't know if the Ultrablock elastic skirt is strong enough for use of these straps. Maybe just a problem for Sleep Number mattresses? (But my fitted twin sheets fit well, so...) At any rate, it seems decent enough - my previous mattress covers were expensive, didn't have these issues - but didn't survive the first washing. Time will tell how well it holds up, and hope I never have to test the rater proof claims! Update: After my review, the manufacturer reached out to me and determined that the original mattress pad was possibly defective. They sent me a new one at no charge. I asked them about using the Jajaplus bed sheet securing straps sold on amazon to keep the pad taught and prevent wrinkling under the sheet (garter style closures instead of sharp tooth clamps like most sheet straps). They responded that these should work fine without damaging the pad. The new pad arrived within days of our conversation, and the Jajaplus straps have eliminated the problem with crease appearing under the sheet, so everything is great. Re-marked the rating as 5 stars because: 1) The manufacturer follows user comments, showing interest in their qualkity control 2) They had rapid response and resolution of a problem 3) They worked with me on an unusual request about their product (use of sheet straps).