yes the 03-04 Duratec's are awsome. 2.3L and is a night and day diffeance over the 2.0L Zetec.
The accel is awsome on the 03-04 2.3L Foci. For those 2 years they changed the final drive gear ratio and it was a good thing. In 05 they went back to the normal Zetec final drive. The 05-07 ST is the one 05+ Focus with the 2.3L in it and it pulls a bit harder than the 03-04 but what the 03-04 has is nothing to sneez at.