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Yesterday I wrote that The Best Value Flight Across the Atlantic Has Almost No Premium Award Space. I was referring to American Airlines’ Los Angeles <-> London route as the best value flight across the Atlantic.

The 11 hour flight features fully flat business class for 50k American Airlines miles each way and fully flat first class for 62,500 American Airlines miles each way.

The plane is brand new and features American’s best hard products as well as an onboard bar.

Compare the prices on this flight to what Delta and United charge for transatlantic premium cabins:

• In business, United wants 57,500 miles each way on its own flights to Europe and 70k miles for partner flights. For United Global First, the cost is 80k miles, and they want 110k miles each way for a First Class flight on partners like Lufthansa.
• Delta charges 125k miles roundtrip in business class. Delta miles can’t be redeemed for three-cabin first class.

Because the product and price is right, I called MileSAAver award space on the Los Angeles to London flight on American Airlines the best value transatlantically.

Twitter wasn’t having any of that:

@MileValue Not sure how that's a better value than BOS-DUB!

— Ben Schlappig (@OneMileataTime) March 19, 2014

@MileValue I would've picked BOS-DUB, I think, as best value award flight TATL.

— Seth Miller (@WandrMe) March 19, 2014

Let me give you three reasons why I think Los Angeles to London is a better value than their candidate Boston to Dublin on Aer Lingus with Avios.

The flight that Ben and Seth contend is a better value is the Boston to Dublin flight on Aer Lingus. Aer Lingus is a partner of British Airways, so you can use Avios to book the flight.

British Airways award prices are based on distance flown and completely ignore regions. Boston to Dublin is only 2,993 miles, so it just sneaks into the band on British Airways’ award chart that costs only 12,500 Avios one way in economy and 25,000 Avios in business class.

British Airways collects small fuel surcharges on Aer Lingus flights, so the out-of-pocket cost on a roundtrip award is only about $122. A roundtrip to Europe for 25k Avios + $122 is fantastic, as is a roundtrip in business class for 50k Avios + $122. But I think American’s Los Angeles to London route represents better value for three reasons.

1. Los Angeles to London is 10hr40min. London to Los Angeles is 11hr15min. Compare that to Boston to Dublin, which is 6hr5min outbound and 6hr55min back.

Sure you are paying twice as many miles–50k each way versus 25k in business class–but you are getting almost twice as much flying. On redeyes, those extra four and a half hours means an extra four and a half hours of sleep, so you can hit the ground running in Europe on day one. On the return, the extra four and a half hours means more time to enjoy the business class experience.

2. Los Angeles to London offers fully flat beds in business class and first class. Aer Lingus business class is a seat. It’s marketed as angled lie flat, which is what I call a seat.

I can’t imagine falling asleep on the above Aer Lingus seat. Even if I did, of course, it wouldn’t be much because of the short flight time.

3. Connections are free on the Los Angeles to London route; every extra flight on Avios awards costs more Avios.

Like all American Airlines awards, the miles price is determined by the regions of the cities involved and the cabin flown. So even if you don’t live in Los Angeles–say you live in Phoenix, San Francisco, or Honolulu–you can take advantage of Los Angeles to London in a flat bed as part of a 50k mile business class award from your home airport to London or anywhere else in Europe.

Like all Avios awards, every segment adds to the price of the award. So if you don’t live in Boston or want to connect in Dublin to elsewhere in Europe, your award surges in price from 12,500 Avios in economy/25,000 in business to a much higher price.

But there are some good counterarguments. Here are three ways Boston to Dublin is a better value than London to Los Angeles:

1. You cannot get a lower price than 12,500 Avios to Europe and 25,000 in business.

Other cheap ways to Europe:

• You can occasionally pay 13k Virgin Atlantic miles one way to Europe in economy.
• You can fly to Europe for 20k American Airlines miles each way from October 15 to May 15 each year.
• You can fly to Europe in roundtrip business class from parts of the east coast for 63k ANA miles.

Still none of those match the 12,500/25,000 Avios price on Aer Lingus.

2. Avios are easier to get than American Airlines miles.

Avios can be earned with the British Airways Visa Signature® Card and any Ultimate Rewards earning card and any Membership Rewards earning card.

Plus there are often transfer bonuses from Membership Rewards to Avios.

I do think it’s important to consider the ease of earning AAdvantage miles compared to Avios, but it’s also important to consider what one is worth. And there, I see them pretty similarly even though their best uses are wildly divergent.

3. Award space is better on the Aer Lingus flights from Boston to Dublin than the American Airlines flight from Los Angeles to London. I went through all the premium space on the American Airlines flight yesterday, and there wasn’t much. If you can’t book it at the Saver level, it doesn’t offer good value.

Recap

Some very smart people disagreed with my assessment that business and first class on the American Airlines Los Angeles to London flight is the best value transatlantically, preferring to use Avios on Aer Lingus’ Boston to Dublin flight.

I think both sides have strong arguments. Which flight would offer you better value?