<p>Bought the one from Costco. It comes with a cover which I think helps it last. It just finished 1st year of grad school. So 5 years and still good. This is first year son hasn’t come home for more than a few days. Other summers I washed cover and aired/spray disinfected the mattress outside on hammock, before son used it on home bed. Foam is regular twin. Son leaves the gap at head of bed rather than the foot. He says with pillow he doesn’t notice gap. I bought foam for H & I, husband prefers gap at bottom. The foam vs eggcrate was an obcession of mine 5 yrs ago.</p>