Yes, they are the hardcovers (good question). Each "Ultimate" volume contains two regular paperback volumes, and the pages/type are very large. Sometimes, I have trouble reading manga print (especially those little side comments) without bright light, so the large print is great for me. I can read them in normal light.
Note to publishers: I will gladly pay twice the price for hardcover manga titles with large pages and large type. There are some titles that I own in paperback that I would even rebuy as hardcovers.