Ethiopian Airlines has retrofitted all its Ethiopian Boeing 777 passenger aircraft with lie-flat seats in business class, allowing passengers who can pay the hefty ticket prices to sleep on flat beds at the click of a button, Ethiosports reports.

“We are very pleased to provide our passengers with the best on-board experience, especially on our long-haul routes,” said Ethiopian Airlines CEO Ato Tewolde Gebremariam. “Ethiopian Airlines has made the choice of purchasing the 180-degree flat business-class seats because of the enhanced customer satisfaction they bring. Our business passengers will be able to sleep and arrive fresh to their destinations fully rested and ready to take on business after a good night’s sleep.”

Ethiopian is a pan-African global carrier with the youngest fleet on the continent. It has 76 aircraft with 42 on order, and their average age is less than seven years. The airline flies to more than 91 international destinations.

Of Ethiopian Airlines‘ 76 aircraft, 59 are Boeings, and of those, 14 are 777s. The Boeing 787-8 has 24 lie-flat seats in business class and 246 seats in economy class, according to SeatGuru.

So is a lie-flat airplane seat worth the extra cost? And how much will it set you back?

Many business travelers love lie-flat seats, a perk that most large international carriers now offer on certain long-haul routes such as across the Atlantic or across continent, according to USAToday.

“Without a doubt it is worth every penny to ensure that I am rested and prepared when I arrive at my international destination,” said Sue Hershkowitz-Coore, a sales trainer and author who lives in Scottsdale, Ariz.

But those premium cabin snoozes don’t come cheap. A business- or first-class seat on a cross-country or overseas flight can cost thousands of dollars and upgrades sometimes require cash, as well as frequent-flier miles, says USAToday.

Airline seats in business class have been reclining more and more as airlines compete with luxury perks for business travelers who often book expensive, last-minute flights.

Recliner-type seats are being phased out, as are angled flat seats that are almost flat but not quite 180 degrees, Saltzburg said.

“We’re seeing a migration away from those seats to fully flat seats … which are viewed as the most comfortable,” he said.

Passengers who fly less or usually sit in coach may not grasp the nuances that separate a recliner from a fully flat seat. But, Saltzburg said, “the experienced traveler understands the difference.”

And not being clear on what those nuances mean can cost an airline money.

German airline Lufthansa was fined more than $31,000 because of a difference of opinion on the meaning of the word flat, TravelPulse reported.

Business-class passenger Vivek Talwar claimed he was inconvenienced by a lie-flat seat that only partially reclined on his flight from Mumbai to Dallas in September 2008. He said he couldn’t fall asleep and filed a complaint.

Lufthansa, however, argued that a lie-flat seat is different from a fully flat one or a lie-flat bed. Lufthansa had to refund Talwar’s $780 airfare and $156 litigation fees plus a $31,260 fine, ordered by the National Consumer Disputes Redressal Commission.