I used to use a sleeve-style case with my original iPad, and I loved it. Sleeves protect the iPad while you carry it, and let you experience the full slimline awesomeness of a naked tablet when you take it out to use. Then Apple made the iPad 2 and the Smart Cover and that was it. The only time I change cases now is if I need something rugged, or if I’m testing one for review.
But I’m tempted by the Calypso Tab, a lovely leather sleeve for the regular iPad and the mini. It’s a softish hard shell, and it looks fantastic.