Originally Posted by JJeffrey

The BA lounge offers better complimentary food and drink options than the AC, but it's an otherwise unremarkable lounge to spend much time in. After an hour I'm bored out of mind in there.

Also of note is that historically the BA lounge has turned away otherwise eligible pax who are not departing on the BA flight, however they have reversed this policy this year. As an EXP flying to ZRH and CPH I've had no issues accessing the BA lounge 4 times now this year. But YMMV as noted above.

With that much time I'd just try both the BA club and the AC. Don't bother with the AC in terminal A, just go to the B/C club, it's the largest.