Proper installation of the FD contributes to good performance.
1. Outside plate should be parallel to the large
2. 1mm clearance of the bottom edge of the cage plate from the teeth of the large ring
3. Limit screws should be adjusted for large ring/small sprocket and small ring/large sprocket
4 proper cable tension.
Large/large and small/small with rub is normal, as stated above. It can vary. I have more rub on older drive trains then newer ones. The Campy Record 10V on the De Rosa is nearly imperceptible but it has a plastic insert on the outside of the cage.
P1050183 on Flickr
The 2x7 Nuovo Record on the Colnago is very noisy in x-chain configuration.
Drivetrain on Flickr
Can't say for sure, but I think the flexibility of a narrow chain along with chain stay length are major contributors along with cage width..
Now when a triple is in consideration, the FD is often a different design. The Campy FD example in the following pic has a "step" on the inside plate near the bottom. Hard to see in the pic but it is there.
P1030407 , on Flickr
I know there isn't clearance for the ring in this picture. This condition is what alerted me to realize I had a triple FD instead of a double. It ended up on the Pinarello. Another way you can id the difference is to look at the "arm" with Record stenciled on it Note the location of the "D" relative to the limit screw.