I flew from CDG to JFK on AF012 (777) in Prem Econ today and it was far superior to DL Econ Plus. AF has 8 seats per row, instead of 10, which is what the Econ section has. There are only 3.5 rows and they are in a separate section of the cabin, separated from both business and economy by partitions, not curtains, so it is calmer, although a crying baby would not be fun. Food is the same as economy, which on AF international is okay, not great. AF wines are excellent in any class and service is attentive. I flew over to Europe last week in business on KLM and back in Prem Econ. For the daytime return, Prem Econ is fine, IMHO, and saves quite a bit. For the eastbound overnight, it would be much less comfortable than business and not that much better than economy. The seats recline a bit more but you still have to sleep upright.

It's interesting how many details have been planned to place this service ahead of economy and behind business. The menu is much more plain than in business but a bit fancier than in economy, although the food is the same. You get an amenity kit, which some say is the same as business. It's pretty minimal and not very useful but I don't think economy gets one. You get nicer headphones. I think the screen is larger but I"m not certain about this.

One important factor--if you decide to go business one way and return in Prem Econ, the lowest prem economy fare won't combine with a business class one way so you end up paying several hundred more for Prem Econ than you would if you did a RT in that cabin, but it's still $1500 less than in business.

I will definitely plan future international travel with the AF Prem Econ in mind whereas DL's (and KLM's) econ plus are not worth trying to get. However, if you fly AF , then you have to deal with CDG, which is a horrible airport for transfers and even worse if you have to overnight in the CDG area.