Have you looked into flying AF so you don't have to change terminals?
Thanks for the suggestion. I checked AF, and it's much more expensive. AF is about $300, while BA is less than $100. (And, BA's schedule works better for my schedule.)
Flying is definitely the better option than taking the Eurostar if you're already at LHR.
Thanks for confirming my research!
And if you have elite DL status, you will be in what I think is the best SkyTeam lounge in Europe.
I don't have SkyLounge access by virtue of my DL status, as I'm only a DL Silver. But, question: will my AMEX Platinum permit me to access the Delta SkyLounge during my layover? As we all know, Platinum cardholders can access SkyLounges when they're show a boarding pass for same day travel. My Delta boarding pass will, of course, reflect that I recently landed. But, I haven't found a good definition of "same day" travel.
Does it have to be only for Delta travel that has yet to take place, or does it include Delta travel that has already concluded?
Thanks to everyone for the help!