I'm flying through PHL and found that the new Admirals Club PHL opened at 5am today. En route to the BA club, I saw a sign after security saying that the new Admirals Club was now below Gate A6.
The entrance to the club was a little hard to find, since it's a nondescript door behind a partial wall. There are stairs and elevators to take you downstairs.
At the desk was one American and one US Airways agent. The club itself is kind of small, but it was not that busy. There are small work rooms off the main room (no doors). The bar area has the standard snacks (chips, biscoff type cookies, fruit, tea/coffee). Soup and cheese/crackers were put out around 3pm.