Originally Posted by
Artpen100
The main differences to me are that transiting LHR gives you a little less time to sleep on the overnight flights from the east coast US, and the bag screening at LHR for connections being very slow. All in all, I think CDG is the smoother connection, at least in T2 AF terminals.
As your flights were this summer, you'd find that the CDG connection has become even a lot easier since then as transit security was removed from US flights at the end of 2022 (but was still there when you transited there, even though you found CDG was already better than LHR).