Delta and Air France/KLM have a very close relationship. As founding members of the Skyteam alliance, they also have a tight-knit joint venture that allows them to own a huge portion of transatlantic travel. While this relationship continues to grow (I sometimes hear, "Thank you for calling the Delta, Air France, and KLM elite line, how many I help you?" when I call Delta), their frequent flyer programs are quite different. And since they are both 1:1 transfer partners of American Express Membership Rewards, I often get asked which airline is best for booking Skyteam awards. In short, it's usually Delta, but there can be a few exceptions. I'll explain below.
The Delta Skymiles program is often criticized for making it hard to redeem low level awards (like 25,000 round-trip domestic coach seats or 100,000 US-Europe business class awards), but it can be very generous - especially when it comes to Skyteam awards because they are always at the low level.
The other main advantages of Delta are:
1) Much lower fees. I pulled up a sample Washington DC - Paris roundtrip in coach and Delta's price was 60,000 miles and $84.30. Air France's award came in at 50,000 miles, but cost a shocking $476.86 in fees.
2) Delta is much more generous with miles. They award 100% accrual on most fare classes whereas Flying Blue awards are as low as 0% for cheap fares. Delta also has partnerships with a multitude of non-air partners, like shopping malls, hotels and dining programs.
3) Delta allows awards to be booked 11 months in advance, where Air France only allows 10 months. So basically Delta frequent flyers get to book Flying Blue awards before Flying Blue members. Seems a little backwards, right? Check out these screenshots for an example - I can currently book a Paris - NY flight on January 2nd using Delta miles, but not with Air France's own Flying Blue miles:
4) American Express runs frequent transfer bonuses to Delta like the current 30% and 50% and 25,000 MQM offers.
Flying Blue does have a couple unique advantages.
1) The ability to book one way awards. If you wanted LAX-CDG in coach one way, you'd pay 25,000 Flying Blue miles versus 60,000 Delta miles.
2) They run crazy 50% off awards, which can be incredible values - especially for longhaul premium class travel.
As always, the best choice for you is the one that best aligns with your travel plans. For instance, I'm currently helping clients book an award trip to Africa and British Airways makes the most sense on the outbound, but they will return on Air France. Since they have American Express Membership Rewards points, I advised them to transfer miles to both programs and leverage one-way awards.
I still think the most standout advantage between programs is that millions of Delta Skymiles members have access to Flying Blue awards before Flying Blue members. This is a huge benefit - especially when booking high demand awards like LAX- PPT (Papeete, Tahiti).
