I have the standard borgy with its 5 speed ratio, which i think is 3.89. Its ok, but its a little hard in traffic as 60 and 100 are gut less in the gears you would use at that speed, to just maintain momentum. Just a 500 rpm increase puts you into a useable area of the rev range, if you know what I mean. Its particularly evident due to the light flywheel. Anyhow, in my opinion, having not driven the 4.1 yet, the 4.1 would be a better daily driver diff. A little bonus accelleration, and ill sit a little higher rpm at the speedlimits, so ill have some ponys with less requirement for a downshift each time. Go the 4.1, trd sells 4.77s so 4.1 is quite tall for such a revvy motor, imo. How many atmo 1.6litre engines will pull 120 in second, my commodoore couldnt do that and it was 3+ litre!