I toured the world's first Airbus A321XLR business class. The lie-flat seats lack one popular feature — but are easy to love anyway.

The Thompson Aero Vantage Solo seats are configured in a 1×1 layout, meaning all passengers have direct aisle access. Flyers will get the standard business-class perks, like priority boarding and hot meals.

The section takes up about one-third of the cabin, while the rest of the plane hosts 168 economy seats in a 3×3 layout. There is no premium economy.

The lie-flat beds are likely a welcome feature for flyers during the seven-hour trek between the US and Spain. Iberia provides plush linens for sleeping.

I thought the beds were long enough for my five-foot, three-inch tall self, but they were too narrow to comfortably sleep on my stomach. Customers should have enough room to sleep on their side or back.

Few airlines offer Bluetooth-capable televisions so I was excited to see the option on Iberia — which also extends to the economy cabin.

I would prefer to connect my AirPods, but customers without Bluetooth headphones can use the headset provided by Iberia.

With minimal cabin real estate for business class, Iberia got creative with storage. Beyond the tabletop space and overhead bins, flyers have nooks beside the seat and below the television.

A larger backpack likely won't fit, but chargers, books, electronics, and other small items needed during the flight can be at arm's length.

JetBlue Airways has the same business-class seat on its Airbus A321neoLR, but it comes complete with sliding doors — something that has become a flyer-favorite perk in modern business-class cabins.

Iberia has not equipped its A321XLR with doors, instead relying on the seat's angle and high wings for privacy. I think the design easily does the job, and the swing-out television helps further cacoon passengers.

A fully private space is preferred among many travelers, but I think adding a door would take up unnecessary space and add costly weight that Iberia likely didn't want to take on.

Another popular trend among new business-class cabins is larger front-row seats, which typically have extra space for a bigger bed or a companion seat but come at an extra fee.

JetBlue, for example, has its "Studio," while Virgin Atlantic Airways has the "Retreat Suite." Iberia's entire A321XLR business cabin is equipped with standard seats, which was likely the best way to optimize the cabin.

Designating an extra-large front row would also likely decrease the number of Iberia's regular high-dollar seats available to sell.

The A321XLR is a smaller long-haul plane, so its likely more passengers will be visiting the lavatory during the flight.

The front of the cabin has one lavatory for up to 14 people, which will be fine so long as the flight attendants keep it clean and stocked.

Business class passengers will likely be happy to have their own bathroom as the 168 economy flyers have to share the three at the back — and there's very little room to queue.

Airlines like JetBlue and Ireland's Aer Lingus have flown narrow-body planes with lie-flat business class for years, and American has a lie-flat cabin on its transcontinental fleet.

American is bringing that strategy to its future A321XLR with a new and improved business class — and this time with sliding doors and direct-aisle access for all travelers.

United is also planning a lie-flat cabin, though details are limited.

The A321XLR is a versatile plane that can fit into both mainline and low-cost fleets — meaning some examples of the jet will not have business class.

Hungarian budget carrier Wizz Air recently announced a seven-hour A321XLR flight between London and Saudi Arabia. The flight will be all-economy with minimal legroom and no fancy amenities.

Wizz Air CEO József Váradi said in September that the no-frills cabin will keep prices cheap, but customers will "have to create the fun for yourself."