Thanks.

Our bags were indeed ITI tagged so they were checked through to Europe. Arriving in ATL we used ESTA to go landside and used the train to reach concourse F. We had plenty of time to visit the lounge but it turned out there was no food whatsoever there (Is that normal at 8PM?). So we headed to the food court upstairs where I actually quite enjoyed the food at the Taco place.

Besides KLM/Delta having messed up our reservations due to a last-minute change (Irrelevant to the ATL transfer) the experience in ATL was quite good. A lot better (faster) than expected for sure. The Skyclub may just as well be skipped through - the only thing readily available there is booze...which I believe is not free.