I agree that the B757 has a heigh power/weight ration, but if you look at ect. A300-600R, it has the same ration. I can tell you, that the takeoff in the A300-600R is very powerfull, and the climb is very steep.
A have flown:
A300-B4, A300-600, A310-200, A310-300, A330-300, A340-300, B720B, B727-200, B737-200 -300 -400 -500 -700, B747-200 -300 -400, B757-200, B767-200 -300, B777-200, L-1011, DC-10-30 -40, DC-9, MD-80, F70, Bae146, Caravelle, and Concorde.
The is not that big different in the takeoff power on the different types (except Concorde), as it also has to do with fuelload, wind, temperature ect ect.
So, Airbuses has NOT less powerfull takeoff.