No airline flies Detroit to Pisa nonstop in business class, so you're routing through a hub — and each carrier brings a distinct product to the table. Delta's Delta One Suite, likely connecting via Amsterdam or Paris on partner metal, gives you a closing door and genuine privacy in a 1-2-1 layout, plus a Tumi amenity kit that's a cut above the standard offering. United's Polaris seat is a similarly private lie-flat pod with Saks Fifth Avenue bedding and access to Polaris lounges at connecting hubs like Newark or Chicago. American's Flagship Business suite, paired with Casper bedding and Flagship Lounge access domestically, is a strong choice if your connection routes through Philadelphia or New York. Air France's business cabin, connecting through Paris, leans into the onboard experience with French haute cuisine and access to the La Première lounge at CDG — a nice touch if you have a longer layover. All four are 1-2-1 configurations, meaning aisle access for every passenger, which matters a lot on a red-eye this long.