Comfortable and supportive. It’s been great to have 2 twin XL mattresses with their own separate bases be seamlessly fitted next to each other to form a King size bed that still fits our antique four poster frame. My husband and I can enjoy our own unique preferential settings while still sleeping next to each other. Would definitely recommend for couples who have very different sleeping preferences who still want to be able to sleep next to one another without compromising comfort. We’ve both have been able to sleep amazingly well. 10/10