Ratios do matter. My 1.8 Duratec 4/4 with the MT75 was quicker off the mark than the 2.0l Duratec +4 with the Mazda box. When you dropped the clutch for a quick getaway with the 1.8 it was off in a blink. With the +4 there is a fraction of a seconds delay as the revs sag and the engine finds the torque for the longer ratio. The difference was quite noticeable negotiating busy roundabouts when I first got the +4. I couldn’t be as cocky as I was in the 4/4 pulling out into the traffic. Obviously there were other differences with the boxes but I do miss the MT75 in many ways.
Others will know better but I believe that your 1.8 Duratec still had a 4.1 axle ratio from the factory? That would explain the nimbleness with the MT75 gearbox. The gear spacing was made for heavy cars so the first gear was very very short, even with a 3.7 final ratio like my Roadster Series 2 also had such a gearbox. The first gear and the second gear were very short (the first almost not usable and not used) and the fifth gear was much too long. Actually, only third and fourth gear really fitted. Together with the 1.8 Duratec it was probably a better fit than with a 3.0 V6.