I think all Boeings are a little overpowered and Airbuses may be a little underpowered, here's why.
Boeing 767-300: MTOW ~415,000 lbs.
thrust per engine ~63,000 lbs.
Airbus A330-200: MTOW ~510,000 lbs.
thrust per engine: ~72,000 lbs.
The Airbus weighs like 100,000 pounds more than the 763, yet each engine only makes 10,000 lbs. of thrust more.
I used to work on the groundcrew and have seen both take off, the 763 really gets on it quickly and takes of very fast while the A330 is slow off the start and takes off a bit slower than the 763. If you're all gonna say well it weighs more, bla, bla, bla... When I saw DC-10s take off, they were almost as fast as a 763 and it weighs like 580,000 lbs., so it wasn't underpowered for takeoff. My preference is that I'd rather be in the overpowered aircraft, so it's Boeing for me (if I can help it)