Originally Posted by
prgboy
No-expiration of miles with Delta is a major benefir from my perspective.
I also noticed the 1-way business flights between US and EU are no more 60.000 like they used to be (last used this way in 2016). :-)
Personally, I'd keep Delta and use the miles for intra-US flights.
And yes, there are many more chances to earn miles besides flying in the U.S. than in Europe, seems to me.
Lowest level Business class flights with Skymiles between US-EU pretty much all require a roundtrip booking now (on both DL and partner metal due to award harmonization last Fall). There are still some US markets outside of US-EU routes where this is not true (JFK-BOG, for example), but it largely depends on whether or not revenue fares require roundtrip bookings for cheapest fares or not. There are sometimes decent deals with Skymiles for business fares, but these are generally limited to the irregular 48-hour flash sales and sometime limited unannounced award sales.
There is currently an unannounced D1 Skymiles sale going on between US and a number of EU markets from 180K miles roundtrip (153K miles with 15% Amex discount), but these are only good on flights through May 8th. A roundtrip booking is required for these awards (you can't book them as one-ways for half the miles).