I'm searching for flights to Europe in December and I'm finding a few "E" fare basis itineraries that are slightly cheaper ($100RT) compared to other flight combinations ($900 to 1000 AI).

I'm used to seeing L/U/T as the cheapest economy tickets but I recall Delta adding a new E basis some months ago ... this is the first time I've actually had it come up in a Delta.com search.

The miles earning table at Delta.com indicates an E-fare does earn 100% RDM and EQM. These are DL coded and operated flights, but are TATL so no elite upgrades possible anyways.

Is there some restriction or drawback I'm missing ? Thanks.