In reply to both your posts:
I have driven the 320d automatic, the 325i automatic, the 325 manual and the 330i manual.
Yes - maximum acceleration for any given gear often occur at the torque peak. But maxium acceleration for any given SPEED often occur at the horsepower peak. And since the 325 has much more horsepower it will be able to accelerate faster. This is simple physics.
However you do need to keep that 325 boiling. And that was what I meant by "well driven".
The 320d is a proper BMW - no doubt. But that car doesn't need those wheels!! They are just to good for it. I'm very against "over-wheeled" and "under-motored" cars in general...