eefor jfp

For me the difference is that the F lounges at T3 with the exception of BA's F dining room are all available to oneworld emeralds whereas the Concorde Room in T5 is only available if you're actually flying first (or, I guess, if you're GGL). So that makes it a little bit special and If I were paying for an F ticket, I would consider going with BA from T5.
But if your final destination is Atlanta, then I agree with HogwartsExpress that the direct flight with F supersedes any other routing that triggers an extra stop (unless you need the tier points in which case you can go via JFK, MIA or DFW and experience AA's F dining as well as the CCR in T5).

HeatherT2408

We're using airmiles and a companion voucher so other routines probably wouldn't work unless it was direct to/from DFW but they don't have F seats at the time We're going, May 2025. I assume we were able to get F availability because LHR-ATL isn't a popular route, other routes I checked link miami had no availability for reward flights.
all in all I think we'll stick with T3, still get some decent lounges, F flights and direct to the location we need to go to. If F becomes available for DFW could look at changing if there was availability.

mikeyfly

Oh didn’t realise you were on 241. In which case ATL has quite generous amounts released. I’d stick with that and keep it simple. I wouldn’t let an hour or two in a lounge influence my decision

Koru Flyer

ATL has an excellent Amex Plat/Centurian lounge

PETER01

Welcome to Flyertalk and here at the BA Forum HeatherT2408

Good advice above there and any more queries then fire away. The knowledge here is really quite remarkable and of course there is also the USA forums should you need any advice on your roadtrip.

flatlander

In T3, the BA F lounge is quite OK and often fairly quiet. The CX lounge is great when it's quiet and still OK when busy. The QF lounge (business, not F) is an impressive place to have a cocktail but the food options are not extensive and there's no quieter places to relax. AA F is like a very grey, very upscale hotel lobby but it's usually quite quiet.

My preference is to go to CX F and eat, and if it's quiet enough to get a comfortable seat then stay there, otherwise go over to BA F. Unless I'm in a great hurry in which case the buffet at BA wins over waiting for table service at CX.

HeatherT2408

Thanks all, really helpful advice. One other lounge related question is there a limit to how early you can check in and go to the lounge? Our flight is 16:15. Thanks

RetiredATLATC

Massive understatement

BertieBadger

No limit, check in and visit as early as you like.

Some people may counsel against arriving early on the basis that lounges are nothing more than glorified waiting rooms, and obviously at one level that is true, but waiting while enjoying food and drink with good company in comfy surroundings can be a worthwhile pleasure in itself. You've already said that this is something of a treat that you're not likely to repeat, so I would personally suggest not to put too much weight on any opinion where familiarity has possibly bred a degree of contempt.

In other words, I'd err on the side of spending longer in this circumstance, especially if you plan to visit multiple different ones (and why not, see which you enjoy the most)

alexwuk

The First dining section of the BA lounge in T3 is very nice and isn't just for dining. It was plenty of natural light and comfortable seating away from the tables. It's generally very quiet as it's GGL/F pax only.